John's Astronomy And Astrophotography Wiki - User contributions [en]

Template:Documentation

2026-02-05T03:51:11Z

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2026-02-05T03:50:43Z

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Sandbox

2026-02-05T03:43:46Z

Jmh921: Created page with "This is a sandbox page for testing formatting {{coord|65|31|N|95|56|E|type:landmark_scale:300000|display=inline,title}}"

This is a sandbox page for testing formatting

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Common Equipment Standards

2025-06-09T02:41:43Z

Jmh921: Created page with "This page is intended to hold information about commonly used standards for equipment used by amateur astronomers. ==Eyepiece Formats== There are three common formats for ey..."

This page is intended to hold information about commonly used standards for equipment used by amateur astronomers.

==Eyepiece Formats==

There are three common formats for eyepieces based on the diameter of the eyepiece's barrel flange and the focuser's receptacle. These are typically described using imperial standard measures.

0.965 inch

1.25 inch

2 inch

==Threads==

{| class="wikitable" style="margin:auto"
|+ Threads commonly found on astronomical equipment <ref>https://astrobasics.de/en/components/thread-types/</ref>
|-
! Common Name !! Specification* !! Common Uses !! Notes
|-
| T2 || M42x0.75 || (Need info here) ||
|-
| SCT Thread || 2"x1/24" (50.8x1.058 mm) || SCT visual backs || Typically found on the back of Schmidt-Cassegrain telescopes for attaching a visual back.
|-
| C-Mount || 1"x1/32" (25.4x0.794 mm) || Camera lens mounts || Often used to attach lenses to cameras where a proprietary connection is not used (e.g. Nikon or Canon lens mounts). Usually has a back-focus distance of 17.526 mm.
|-
| CS-Mount || 1"x1/32" (25.4x0.794 mm) || Camera lens mounts || Similar to C-Mount, but usually has a back-focus distance of 12.526 mm.
|-
| 1.25" Filter Thread || M28.5x0.5 || Commonly used for attaching filters to 1.25" eyepieces. || Some manufacturers use a 0.6 thread pitch.
|-
| 2" Filter Thread || M48x0.6 || Commonly used for attaching filters to 2" eyepieces. || Some manufacturers use a 0.75 thread pitch.
|-
| Camera Tripod Thread || 1/4"x20 (6.35x1.27 mm) || Attaching cameras to tripods || Found on most DSLR and other consumer cameras as well as many small telescopes and other items.
|-
| Larger Camera Tripod Thread || 3/8"x16 (9.53x1.5875 mm) || Attaching larger cameras to tripod || Commonly found on medium and large format cameras. Also used by the ZWO SeeStar Smart Telescopes.
|}

* If the specification is not normally given in metric, metric is included in parentheses.

Tutorials

2025-04-28T18:38:52Z

Jmh921: Created page with "This page is intended to hold links to a variety of tutorials for amateur astronomy and astrophotography. If you have a link to add and do not have access to editing content,..."

This page is intended to hold links to a variety of tutorials for amateur astronomy and astrophotography. If you have a link to add and do not have access to editing content, please contact the manager of this site at johnhaynes@jmhastronomy.com [mailto:johnhaynes@jmhastronomy.com?Subject=Requesting%20changes%20to%20AstroWiki%20Tutorials%20Page johnhaynes@jmhastronomy.com]

=General Astronomy=

=Astrophotography=

==General==

[https://naplab.com/guides/astrophotography-guide/ Sleeping Under the Stars: A Beginner’s Guide to Stargazing and Astrophotography]

==Equipment==

==Image Capture==

==Processing==

===Pixinsight===

[https://www.pixinsight.com/tutorials/ Tutorials on the Pixinsight website]

[https://www.mastersofpixinsight.com/ Masters of Pixinsight]

[https://web.archive.org/web/20220315073829/https://www.lightvortexastronomy.com/ Light Vortex Astronomy] (The site is no longer active, but is available via the Wayback Machine).

=Amateur Telescope Making (ATM)=

[https://stellafane.org/tm/index.html Stellafane's Telescope Making Site]

Refractor Telescope

2025-01-30T16:09:58Z

Jmh921: Created page with "A refracting telescope, or refractor, is a type of telescope that uses lenses to collect and focus light. Refractors were the first telescopes constructed with their history..."

A refracting telescope, or refractor, is a type of telescope that uses lenses to collect and focus light. Refractors were the first telescopes constructed with their history going back to at least 1608.<ref>There is some debate as to who invented the telescope and when, but the first documented reference is a patent application submitted to the States General of the Netherlands by Hans Lippershey, a spectacle maker living in Middleburg. However, the patent was rejected as the invention was considered not a new innovation. This strongly suggests that other telescopes had been made by that time.</ref>

Refracting telescopes have one or more lenses mounted at the front-end of the tube, known as the objective <ref>These are sometimes mistakenly referred to as the "primary," but the correct term is "objective." Primary is the term used for the main mirror in a reflecting or catadioptric telescope.</ref>, and one or more lenses placed at the [[focal point]] of the telescope, referred to as the eyepiece.

==Advantages and Disadvantages==
The primary advantages of a refractor include:<ref>https://personal.math.ubc.ca/~cass/courses/m309-03a/m309-projects/wong/pro.html</ref>
* Superior revolving power per inch of aperture
* Superior performance in inferior conditions and steadier images
* No reflections or interruption of light path
* Rarely need [[collimation]] and minimal maintenance
* The longer focal ratios that are typical of most refractors perform better than other designs with longer focus and simpler eyepieces

The main disadvantages of refractors are:<ref>https://personal.math.ubc.ca/~cass/courses/m309-03a/m309-projects/wong/pro.html</ref>
* A higher price per inch of aperture compared to reflectors and (usually) catadioptrics.
* [[Chromatic Aberration]], an optical aberration that causes
* Long focal ratios can mean that the instrument is cumbersome

==notes for ongoing development==

A refracting telescope's main advantages include: superior image quality with excellent color correction, minimal maintenance due to a sealed optical tube, ease of use with fewer moving parts, a stable and uninterrupted light path, near-permanent optical alignment, and better performance in poor viewing conditions, making them ideal for planetary observation and astrophotography where sharp details are crucial; however, they can be more expensive to manufacture due to the challenges of producing large, high-quality lenses and may suffer from chromatic aberration if not properly designed.
Key advantages of a refracting telescope:
High image quality:
Refractors generally produce sharp, detailed images with good color fidelity, especially when using high-quality apochromatic lenses.
Low maintenance:
With a sealed optical tube, refractors require minimal cleaning and adjustments to maintain alignment.
Ease of use:
Simple design with fewer moving parts, making them user-friendly for beginners.
No central obstruction:
Unlike reflectors, refractors have no central mirror obstruction, allowing for better contrast in the image.
Portable and compact:
Can be relatively lightweight and easy to transport, making them suitable for travel.
Wide field of view:
Some refractor designs can offer a wider field of view compared to certain reflectors.

Astronomy Clubs

2025-01-29T19:01:42Z

Jmh921: /* United States */

An astronomy club or astronomical society is an organization, usually composed of amateur astronomers, for the advancement, enjoyment, and participation in astronomy.

Generally speaking, astronomy clubs are focused on education of the public toward astronomy and astronomy-related subjects and the promotion of astronomy as a hobby. While the particular activities and focus of such clubs varies from group to group, they are all generally interested in advancing awareness and sharing in the wonder of astronomy.

Below you can find a list of astronomy clubs around the world. Please feel free to add your own if it is not listed.

=Why Join a Club=

As mentioned above, the specifics vary from club to club, however, there are common trends among most clubs.

Most clubs conduct regular, most often monthly, meetings. For most clubs this includes a discussion of club business, but the focal point is some form of presentation on a specific topic. The topic may include such topics as using, maintaining, or constructing telescopes, techniques concerning astrophotography, or discussions of visible objects in the night, or it may be a more broadly-based discussion of astronomy, such as discussing the life cycle of stars, recent discoveries in exoplanets, the physics behind star formation, or even community-related topics such as light pollution and what can be done to improve it. Some clubs have multiple sessions aimed at beginners and more advanced members. Many clubs also conduct workshops and training classes for observing and using telescopes.

===Dark Sites===

While most clubs conduct meetings like this, they tend to be more centered around observing activities. In such clubs, many members own telescopes and, in fact, may have joined in order to learn more about using and maintaining their telescope. To this end, many clubs either own or have access to a piece of land reserved as an observing site, or a "dark site." A [[Dark Site]] is a place reserved for observing where light pollution is better regulated. Most such places are outside of major cities, but within relatively easy driving distance. They typically are shielded from major roads by walls, fences, trees, and/or bushes and usage of light, particularly white light, during observing times is generally restricted (see [[Light Discipline]] for more information).

Not all clubs have access to their own dark site. However, in those cases, members of the club will usually have scouted out areas that are generally conducive for observing activities. Such locations are often found in municipal parks in a city or town, or in state parks or nature preserves outside of town. The primary features of such sites are little traffic/stray light and skies with noticeably less light pollution than in the city.

===Star Parties===
Many clubs also conduct regular star parties. A [[star party]] is a gathering, often at a club's dark site, where those who have telescopes bring them out and the assembled members and guests spend an evening observing. Most telescope owners are generally happy to let others look through their telescope, and many are happy to talk all about the equipment being used and the object(s) being viewed. Star parties may simply be gatherings of members or may have a focus on outreach. Many clubs also offer to conduct them for schools and community organizations.

Those clubs that own their own dark site or have access to one in association with a school, business, or other organization sometimes also have their own observatory or access to an observatory, at which one or more telescopes are permanently mounted in a facility designed for the purpose. These telescopes are often larger and/or more expensive and complex than most members would have the ability to purchase, though sometimes they're more modest systems. Clubs that have observatories typically have a process for members to be able to access them.

Star parties are also a great way for those who don't have telescopes to learn more about them before they purchase. Attending a star party will usually allow a member to look through several different types of telescope and give him or her a chance to talk to the owner about the experience of owning a particular type of telescope.

===Loaner Telescopes===

Some clubs also have club-owned equipment for users to borrow. Loaner scope programs often provide access to fairly common telescopes to members and may serve as a way for members to try out different types of telescope before they spend the money themselves on their own.

===Astronomical League===

In the United States, most local clubs are also members of the [https://www.astroleague.org/ Astronomical League], or AL, which serves as something of a parent organization for astronomy clubs and societies in the US as well as offering "member at large" membership to those not part of a specific club and those outside of the United States. Among the benefits of membership in the AL is access to their [https://www.astroleague.org/observing.html Observing Programs]. The AL Observing Programs are designed to help provide a purpose and direction to observations (giving those who participate a sense of a mission to accomplish). Many such programs award a certificate and/or pin to commemorate the observer's achievement. For example, those who complete the [https://www.astroleague.org/al/obsclubs/messier/mess.html Messier Observing Program] will get a certificate after observing 70 of the 110 objects in the [[Messier Catalog]], and observation of the full list of 110 will earn a certificate and pin. To qualify, the observations must be logged with specific information and this information must be approved (either by a local club official or by the national coordinator).

===Club Dues===

Most clubs in the United States are 501(c)(3) non-profit organizations. However, most do charge annual membership dues to maintain club equipment and facilities and to do such things as pay for guest speakers and awards.

In the US, at the time of this writing (October of 2019), club dues for most local clubs cost $50 per year or less, with many being significantly less. Many clubs also prorate club membership depending on the month in which a member joins.

For example:

*The [http://www.astronomyhouston.org Houston Astronomical Society] in Houston, TX, currently charges annual dues of $36 per year for a standard membership (there are also senior, student, and family rates). If a member joins in October, they would pay only $9 (a rate of $3 per month times 3 months) for the remainder of the year, then pay the full $36 at the beginning of the following year for that year's membership.

*The [http://www.rivastro.org/index.php Riverside Astronomical Society] in Riverside, CA, has an introductory rate of $20 for individuals, with a renewal rate of $40, and offering "Patron" memberships of $100, $200, and $300 per year for Bronze, Silver, and Gold memberships (respectively).

Not all clubs prorate, but it is fairly common. Other clubs handle dues on a rotating-year model (e.g. if you join in October, your membership is good through the next October, at which time you must renew). Contact your local club for specifics concerning dues.

For clubs that are members of the Astronomical League, typically a portion of your regular dues is used to pay your membership in the AL. The cost of AL membership for members of member clubs is typically significantly less than membership-at-large.

For clubs outside of the United States, the cost will vary.

=Lists of Clubs=

===United States===

*[https://www.astroleague.org/astronomy-clubs-usa-state Astronomical League] The Astronomical League is a collection of clubs throughout the United States. The link provided will allow you to find a club near you within your state.

*[https://nightsky.jpl.nasa.gov/club-map.cfm Night Sky Network] The Night Sky Network, or NSN, is a partnership between NASA/JPL, The Astronomical Society of the Pacific, numerous individual astronomy clubs and societies, the Institute for Learning Innovation, and several other organizations with an interest in science, astronomy, and education. They include a listing of clubs and events, searchable by Zip Code.

*[https://www.go-astronomy.com/astro-club-search.htm Go Astronomy Club Lists] Go Astronomy is a website with a variety of resources for astronomy, and worth a look for many reasons. They also include a very extensive directory of clubs, societies, observatories, and planetariums, mostly n the United States.

*[https://www.skyandtelescope.com/astronomy-clubs-organizations/ Sky And Telescope] Sky And Telescope magazine's online site also has a database of clubs, organizations, museums, observatories, and more. Their content is focused on the United States, but includes international content as well. Their database does not appear to be particularly well curated, however, and club listings may be out of date.

{| class="wikitable sortable"
|+ '''List of Local Astronomy Clubs In the United States:'''<ref>https://www.astroleague.org/astronomy-clubs-usa-state/</ref>
|-
! style="text-align:left; width: 30%" | Society Name
!! style="text-align:left;" | City
!! style="text-align:left;" | State
!! style="text-align:left;" | Address
!! style="text-align:left;" | Website
!! style="text-align:left;" | Facebook Page
!! style="text-align:left;" | Member of the Astronomical Legue
|-
| Auburn Astronomical Society || Auburn || Alabama || || http://www.auburnastro.org/ || || ''✓''
|-
| East Valley Astronomy Club || Mesa || Arizona || P.O. Box 2202 || http://www.evaconline.org || || ''✓''
|-
| Prescott Astronomy Club || Prescott || Arizona || Prescott Astronomy Club186 E. Sheldon St. #1122 || https://prescottastronomyclub.org/ || || ''✓''
|-
| Phoenix Astronomical Society, Inc. || Scottsdale || Arizona || 7979 E Princess Dr || http://www.pasaz.org || || ''✓''
|-
| Huachuca Astronomy Club || Sierra Vista || Arizona || P.O Box 922 || http://www.hacastronomy.org || || ''✓''
|-
| Tucson Amateur Astronomy Association || Tucson || Arizona || P. O. Box 41254 || http://www.tucsonastronomy.org || || ''✓''
|-
| Sugar Creek Astronomical Society || Bentonville || Arkansas || || || || ''✓''
|-
| Kern County Astronomical Society || Bakersfield || California || 5501 Stockdale Hwy #10241 || https://www.kernastro.org || || ''✓''
|-
| Aerospace Employees Association Astronomy Club || El Segundo || California || 2310 E El Segundo Blvd || || || ''✓''
|-
| Astronomers of Humboldt || Eureka || California || P.O. Box 351 || https://www.astrohum.org || || ''✓''
|-
| Temecula Valley Astronomers || Murrieta || California || P.O. Box1292 || https://www.temeculavalleyastronomers.com || || ''✓''
|-
| South Bay Astronomical Society || Redondo Beach || California || P.O. Box 1244 || https://www.sbastro.net || || ''✓''
|-
| San Diego Astronomy Association || San Diego || California || PO Box 23215 || https://sdaa.org/ || || ''✓''
|-
| TAC - AL (The Astronomy Connection) || San Jose || California || || || || ''✓''
|-
| Bear Valley Springs Astronomy Club || Tehachapi || California || 23871 Lakeview Dr. || https://www.bvsac.org || || ''✓''
|-
| Tulare Astronomical Association || Tulare || California || 1062 N. A. St. || https://tulareastro.org/ || || ''✓''
|-
| Mt. Shasta Stargazers || Weed || California || 134 Shasta Cove N || https://www.mtshastastargazers.com || || ''✓''
|-
| Colorado Springs Astronomical Society || Colorado Springs || Colorado || PO Box 16318 || http://www.csastro.org || || ''✓''
|-
| Denver Astronomical Society || Denver || Colorado || P.O. Box 102738 || http://www.denverastro.org || || ''✓''
|-
| Gunnison Valley Observatory || Gunnison || Colorado || P. O. Box 1227 || https://www.gunnisonvalleyobservatory.org/ || || ''✓''
|-
| Longmont Astronomical Society || Longmont || Colorado || P.O. Box 806 || https://www.longmontastro.org || || ''✓''
|-
| Black Canyon Astronomical Society || Montrose || Colorado || 27 N. Willerup Ave || https://blackcanyonastronomy.com/ || || ''✓''
|-
| Shoreline Astronomical Society || Madison || Connecticut || 83 Wildcat Rd || https://shorelineastronomicalsociety.blogspot.com/ || || ''✓''
|-
| Litchfield Hills Amateur Astronomy Club || Morris || Connecticut || 211 West St || https://www.LHastro.org || || ''✓''
|-
| Delaware Astronomical Society || Greenville || Delaware || Mount Cuba Obervatory1610 Hillside Mill Rd. || https://www.delastro.org || || ''✓''
|-
| National Capital Astronomers || Davidson || District of Columbia || 3804 Wayson Road || http://www.capitalastronomers.org || || ''✓''
|-
| Local Group of Deep Sky Observers || Ellenton || Florida || 5610 32nd Ave E. || http://www.LGDSO.com || || ''✓''
|-
| Alachua Astronomy Club || Gainesville || Florida || 2603 NW 13th St., #161 || || || ''✓''
|-
| Northeast Florida Astronomical Society || Jacksonville || Florida || P.O. Box 5432 || http://www.nefas.org || || ''✓''
|-
| Brevard Astronomical Society || Melbourne || Florida || PO Box 410092 || https://www.brevardastro.org/ || || ''✓''
|-
| Everglades Astronomical Society || Naples || Florida || 270 Naples Cove Drive, Unit 3206 || https://evergladesastronomicalsociety.org/ || || ''✓''
|-
| Moonstruck Astronomy Club || Ocala || Florida || || https://moonstruckastronomyclub.org/ || || ''✓''
|-
| Central Florida Astronomical Society, Inc. || Oviedo || Florida || P.O. Box 620907 || https://cfas.org || || ''✓''
|-
| Escambia Amateur Astronomers' Assn. || Pensacola || Florida || || https://sites.google.com/view/escambiaastronomers || || ''✓''
|-
| Tallahassee Astronomical Society || Tallahassee || Florida || PO Box 824 || http://www.tallystargazers.org/ || || ''✓''
|-
| Astronomical Society of the Palm Beaches || West Palm Beach || Florida || P.O. Box 19652 || https://www.astropalmbeach.org || || ''✓''
|-
| Atlanta Astronomy Club, Inc. || Altanta || Georgia || P. O. Box 76155 || http://www.AtlantaAstronomy.org || || ''✓''
|-
| Flint River Astronomy Club || Brooks || Georgia || 788 Rising Star Rd || http://www.flintriverastronomy.org/ || || ''✓''
|-
| Hawaiian Astronomical Society || Honolulu || Hawaii || P.O. Box 17671 || http://www.hawastsoc.org/ || || ''✓''
|-
| Haleakala Amateur Astronomers || Kula || Hawaii || || || || ''✓''
|-
| Boise Astronomical Society || Boise || Idaho || P.O. Box 7002 || http://www.boiseastro.org || || ''✓''
|-
| Idaho Falls Astronomical Society || Idaho Falls || Idaho || P.O. Box 50262 || http://ifastro.org/ || || ''✓''
|-
| Pocatello Astronomical Society || Pooctello || Idaho || || https://pocatelloastronomicalsociety.com/ || || ''✓''
|-
| Champaign-Urbana Astronomical Society || Champaign || Illinois || Staerkel Planetarium/Parkland College2400 West Bradley Avenue || https://www.cuas.org || || ''✓''
|-
| Rockford Amateur Astronomers, Inc. || Loves Park || Illinois || 6691 Squire Ln. || || || ''✓''
|-
| Twin City Amateur Astronomers, Inc. || Normal || Illinois || 1109 N. Linden St. || https://www.tcaa.club/ || || ''✓''
|-
| Popular Astronomy Club || Orion || Illinois || 11 Deer Run Road || https://www.popularastronomyclub.org/ || || ''✓''
|-
| Northwest Suburban Astronomers || Palatine || Illinois || PO Box 95462 || https://www.nsaclub.org/ || || ''✓''
|-
| Peoria Astronomical Society || Peoria || Illinois || PO BOX 10111 || http://www.astronomical.org || || ''✓''
|-
| Fox Valley Sky Watchers || Sleepy Hollow || Illinois || 164 Hilltop Lane || || || ''✓''
|-
| Evansville Astronomical Society || Evansville || Indiana || P.O. Box 3474 || http://evansvilleastro.org/ || || ''✓''
|-
| Fort Wayne Astronomical Society || Fort Wayne || Indiana || PO Box 11093 || https://www.fortwayneastronomicalsociety.com/ || || ''✓''
|-
| Indiana Astronomical Society || Mooresville || Indiana || P.O. Box 703 || http://www.iasindy.org || || ''✓''
|-
| Ames Area Amateur Astronomers || Ames || Iowa || P.O. Box 1961 || http://www.amesastronomers.org/ || || ''✓''
|-
| Des Moines Astronomical Society, Inc || Des Moines || Iowa || P.O. Box 111 || http://www.dmastronomy.com || || ''✓''
|-
| Black Hawk Astronomy Club || Waterloo || Iowa || 503 South Street || || || ''✓''
|-
| Southeastern Iowa Astronomy Club || West Burlington || Iowa || PO Box 14 || || || ''✓''
|-
| Kansas Astronomical Observers || Goddard || Kansas || 25000 W 39th S || http://www.kaowichita.com/ || || ''✓''
|-
| Astronomy Associates of Lawrence || Lawrence || Kansas || 1082 Malott Hall, 1251 Wescoe Hall Drive || https://astronaal.ku.edu/aboutaal || || ''✓''
|-
| Northeast Kansas Amateur Astronomer's League, Inc. || Topeka || Kansas || P.O. Box 951 || http://www.nekaal.org || || ''✓''
|-
| West Kentucky Amateur Astronomers || Golden Pond || Kentucky || West Kentucky Amateur Astronomers238 Visitor Center Drive || || https://www.facebook.com/groups/496426749191848 || ''✓''
|-
| Baton Rouge Astronomical Society || Baton Rouge || Louisiana || || http://www.brastro.org/ || || ''✓''
|-
| Shreveport-Bossier Astronomical Society, Inc. || Shreveport || Louisiana || 353 Ockley Drive || http://www.shreveportastronomy.com || || ''✓''
|-
| Southern Maine Astronomers || Brunswick || Maine || 179 Neptune Drive,Suite 300 || http://www.southernmaineastronomers.org || || ''✓''
|-
| Penobscot Valley Stargazers || Stockton Springs || Maine || || http://www.gazers.org || || ''✓''
|-
| Howard Astronomical League of Central Maryland || Columbia || Maryland || 8630-M Guilford RdSuite 211 || http://www.howardastro.org || || ''✓''
|-
| Cumberland Astronomy Club || Frostburg || Maryland || || http://www.cumberlandastronomyclub.org || || ''✓''
|-
| TriState Astronomers || Hagerstown || Maryland || 823 Commonwealth Ave || https://www.tristateastronomers.org || || ''✓''
|-
| Westminster Astronomical Society || Westminster || Maryland || P.O. Box 1162 || http://www.westminsterastro.org || || ''✓''
|-
| South Shore Astronomical Society, The || Norwell || Massachusetts || 293 Pine Street || http://www.ssastros.org/testsite/index.html || || ''✓''
|-
| Oakland Astronomy Club || Auburn Hills || Michigan || P.O. Box 210554 || http://www.oaklandastronomy.net || || ''✓''
|-
| Kalamazoo Astronomical Society || Kalamazoo || Michigan || 600 West Vine Street, Suite 400 || http://www.kasonline.org/ || || ''✓''
|-
| Shoreline Amateur Astronomical Association || West Olive || Michigan || P.O. Box 201 || http://www.holland-saaa.org/ || https://www.facebook.com/ShorelineAstronomy || ''✓''
|-
| Minnesota Astronomical Society || Minneapolis || Minnesota || P.O. Box 14931 || http://www.mnastro.org || || ''✓''
|-
| Rochester Astronomy Club || Rochester || Minnesota || Box 513 || http://www.rochesterskies.org || || ''✓''
|-
| Jackson Astronomical Association || Jackson || Mississippi || P.O. Box 12586 || || https://www.facebook.com/groups/jacksonastro/ || ''✓''
|-
| Springfield Astronomical Society || Springfield || Missouri || || https://springfieldastronomy.org/ || || ''✓''
|-
| St. Louis Astronomical Society || St. Louis || Missouri || 13128 Cozyhill Drive || http://www.slasonline.org || || ''✓''
|-
| Astronomical Society of Eastern Missouri || Wentzville || Missouri || 206 Old Chesapeake Dr || https://www.asemonline.org/ || https://www.facebook.com/profile.php?id=100064380775869 || ''✓''
|-
| Yellowstone Valley Astronomy Association || Laurel || Montana || 759 Clarks River Rd || https://yvaamt.com/ || || ''✓''
|-
| Omaha Astronomical Society || Omaha || Nebraska || P.O. Box 34703 || https://www.omahaastro.com/ || || ''✓''
|-
| Keene Amateur Astronomers || Keene || New Hampshire || 94 Pako Avenue || http://www.keeneastronomy.org || || ''✓''
|-
| New Hampshire Astronomical Society || Manchester || New Hampshire || P.O. Box 5823 || http://www.nhastro.com || || ''✓''
|-
| Hopatcong Observatory Astronomy Club || Hopatcong || New Jersey || || https://www.hopatcongobservatory.org || || ''✓''
|-
| South Jersey Astronomy Club || Millville || New Jersey || || https://www.SJAC.us || || ''✓''
|-
| STAR Astronomy Society || Red Bank || New Jersey || P.O. Box 863 || https://www.starastronomy.org || || ''✓''
|-
| Astronomical Society of Toms River Area || Toms River || New Jersey || Ocean County College Building # 13, 1 College Drive || http://www.astra-nj.org || || ''✓''
|-
| Albuquerque Astronomical Society || Albuquerque || New Mexico || P.O. Box 50581 || https://www.taas.org || || ''✓''
|-
| Magdalena Astronomical Society || Magdalena || New Mexico || PO Box 125 || http://magdalenaastronomicalsociety.org/ || || ''✓''
|-
| Rio Rancho Astronomical Society || Rio Rancho || New Mexico || 609 Valley Meadows Dr. NE || http://www.rrastro.org || || ''✓''
|-
| El Valle Astronomers || Taos || New Mexico || 403 Valverde Commons Drive || https://elvalleastronomers.org/ || || ''✓''
|-
| Buffalo Astronomical Association || Buffalo || New York || || https://www.buffaloastronomy.com || || ''✓''
|-
| Mohawk Valley Astronomical Society || Clinton || New York || P.O. Box 52 || http://mvas-ny.org || || ''✓''
|-
| Astronomical Society of Long Island || Huntington || New York || 57 Conklin Lane || http://www.asliclub.org || || ''✓''
|-
| Amateur Observers' Society of New York || Mineola || New York || 425 Horton Highway || http://www.aosny.org || || ''✓''
|-
| Astronomy Section of the Rochester Academy of Science || Rochester || New York || P.O. Box 20292 || https://www.rochesterastronomy.org/ || || ''✓''
|-
| Custer Institute || Southold || New York || 1115 Main Bayview Rd.P. O. Box 1204 || http://www.custerobservatory.org/ || || ''✓''
|-
| Rockland Astronomy Club || Suffern || New York || 225 Route 59c/o Challenger Center || || || ''✓''
|-
| Astronomy Club of Asheville || Asheville || North Carolina || 75 St. Dunstan's Circle || http://www.astroasheville.org || || ''✓''
|-
| Cleveland County Astronomical Society || Boiling Springs || North Carolina || || http://www.ccastro.org || || ''✓''
|-
| Chapel Hill Astronomical and Observational Soc. || Chapel Hill || North Carolina || P.O. Box 3001 || https://chaosastro.org/ || || ''✓''
|-
| Raleigh Astronomy Club, Inc. || Raleigh || North Carolina || || https://raleighastro.org/ || || ''✓''
|-
| Cape Fear Astronomy Club || Wilmington || North Carolina || P.O. Box 7685 || http://www.capefearastro.org || || ''✓''
|-
| Miami Valley Astronomical Society || Beavercreek || Ohio || P.O. Box 340896 || http://www.mvas.org || || ''✓''
|-
| Richland Astronomical Society || Bellville || Ohio || P.O. Box 700 || http://www.wro.org || || ''✓''
|-
| Chagrin Valley Astronomical Society || Chagrin Falls || Ohio || 15735 Huntley RoadPO Box 11 || https://www.cvas.space/ || || ''✓''
|-
| Cincinnati Astronomical Society || Cleves || Ohio || 5274 Zion Rd || http://www.cinastro.org || || ''✓''
|-
| Millstream Astronomy Club || Findlay || Ohio || 2019 Sterling Court || || || ''✓''
|-
| Lima Astronomical Society || Lima || Ohio || P.O. Box 201 || https://limaastro com || || ''✓''
|-
| Toledo Astronomical Association || Sylvania || Ohio || 4815 New England Lane, Apt. 4 || http://toledoastronomy.org || || ''✓''
|-
| Stillwater Stargazers || || Ohio || || https://stillwaterstargazers.com/ || || ''✓''
|-
| Bartlesville Astronomical Society || Bartlesville || Oklahoma || P.O. Box 302 || https://sites.google.com/site/bartlesvilleastronomyclub/ || || ''✓''
|-
| Broken Arrow Sidewalk Astronomer || Broken Arrow || Oklahoma || 829 W. Vicksburg Street || || || ''✓''
|-
| Oklahoma City Astronomy Club || Oklahoma City || Oklahoma || P. O. Box 22804 || http://www.okcastroclub.com || || ''✓''
|-
| Odyssey Astronomy Club || Tribbey || Oklahoma || 30222 Slaughterville Rd. || || || ''✓''
|-
| Astronomy Club of Tulsa || Tulsa || Oklahoma || P. O. Box 470611 || http://www.astrotulsa.com || || ''✓''
|-
| Eugene Astronomical Society || Eugene || Oregon || P.O. box 50395 || http://www.eugeneastro.org || || ''✓''
|-
| Rose City Astronomers || Portland || Oregon || 1945 SE Water Ave || http://www.rosecityastronomers.org || || ''✓''
|-
| Umpqua Astronomers || Roseburg || Oregon || 604 Woodoak Drive || || || ''✓''
|-
| Southern Oregon Skywatchers || Talent || Oregon || 1557 Summer Place || https://www.orskywatchers.org/ || || ''✓''
|-
| Starlight Astronomy Club || Altoona || Pennsylvania || 702 Garden Street || http://www.starlightastronomyclub.org || || ''✓''
|-
| Bucks-Mont Astronomical Association || Ambler || Pennsylvania || 411 Susquehanna Rd || http://blog.bma2.org || || ''✓''
|-
| Chesmont Astronomical Society || Exton || Pennsylvania || PMB 218256 Eagleview Blvd || http://www.chesmontastro.org || || ''✓''
|-
| Amateur Astronomers Association of Pittsburgh || Glenshaw || Pennsylvania || P.O. Box 314 || http://www.3ap.org || || ''✓''
|-
| Delaware Valley Amateur Astronomers || Hatfield || Pennsylvania || 301 Logan Drive || http://www.dvaa.org || || ''✓''
|-
| Astronomy Enthusiasts of Lancaster County || Lititz || Pennsylvania || 325 Rudy Dam Road || http://www.aelc.us || || ''✓''
|-
| Oil Region Astronomical Society, Inc. || Oil City || Pennsylvania || P.O. Box 1535 || http://www.oras.org || || ''✓''
|-
| Central Pennsylvania Observers || State College || Pennsylvania || 345 Ridge Ave || http://www.cpoclub.org || || ''✓''
|-
| Chester County Astronomical Society || West Chester || Pennsylvania || 988 Meadowview Ln || http://www.ccas.us || || ''✓''
|-
| Astronomy Club of Augusta || Aiken || South Carolina || 1430 Morningside Drive || https://www.astroclubaugusta.weebly.com || || ''✓''
|-
| Lowcountry Stargazers || Charleston || South Carolina || P.O. Box 14453 || https://www.lowcountrystargazers.org || || ''✓''
|-
| Midlands Astronomy Club, Inc. || Columbia || South Carolina || P.O. Box 2527 || http://midlandsastronomyclub.org/ || || ''✓''
|-
| Grand Strand Astronomers || Conway || South Carolina || 1771 Alford Road || https://www.gsastro.org || || ''✓''
|-
| Barnard Astronomical Society || Chattanooga || Tennessee || || https://barnardastronomy.org/ || || ''✓''
|-
| Astronomy in the Parks Society || Hendersonville || Tennessee || 150 Roberta Dr || || || ''✓''
|-
| Bays Mountain Astronomy Club || Kingsport || Tennessee || Bays Mountain Park Association853 Bays Mountain Park Road || https://www.baysmountain.com/astronomy/astronomy-club/ || || ''✓''
|-
| Smoky Mountain Astronomical Society || Maryville || Tennessee || 3433 Ridgeway Trail || http://www.smokymtnastro.org/ || || ''✓''
|-
| Fort Worth Astronomical Society || Fort Worth || Texas || 5801 Trail Lake Drive || http://www.fortworthastro.com || || ''✓''
|-
| Hill Country Astronomers || Fredericksburg || Texas || P.O. Box 2043 || || || ''✓''
|-
| Psalm 19 Astronomy Society || Johnson City || Texas || 1216 Byrd Ranch Road || https://www.psalm19astronomy.org || || ''✓''
|-
| North Houston Astronomy Club || Kingwood || Texas || P.O. Box 5043 || http://www.astronomyclub.org/ || || ''✓''
|-
| South Plains Astronomy Club || Lubbock || Texas || 3521 50th StSpace 8 || http://southplainsastronomy.org || || ''✓''
|-
| West Texas Astronomers || Midland || Texas || P.O. Box 3284 || || || ''✓''
|-
| Texas Astronomical Society of Dallas || Richardson || Texas || P. O Box 830742 || http://www.texasastro.org || || ''✓''
|-
| Houston Astronomical Society || Spring || Texas || P.O. Box 131282 || http://www.astronomyhouston.org || || ''✓''
|-
| Salt Lake Astronomical Society || Tooele || Utah || 472 Country Club || https://www.slas.us || || ''✓''
|-
| Springfield Telescope Makers || Springtfield || Vermont || P. O. Box 601 || http://stellafane.org || || ''✓''
|-
| Charlottesville Astronomical Society || Charlottesville || Virginia || || http://www.cvilleastro.com || || ''✓''
|-
| Echo Ridge Astronomical Society || Elk Creek || Virginia || 766 Echo Ridge Lane || || || ''✓''
|-
| Rappahannock Astronomy Club || Fredericksburg || Virginia || P. O. Box 752 || http://www.raclub.org || || ''✓''
|-
| Shenandoah Astronomical Society || Front Royal || Virginia || 168 Hatcher Drive || || || ''✓''
|-
| Northern Virginia Astronomy Club || Oakton || Virginia || P.O. Box 3452 || http://www.novac.com || || ''✓''
|-
| Richmond Astronomical Society || Powhatan || Virginia || 1385 Quarter Mill Ct || http://www.richastro.org || || ''✓''
|-
| Blue Ridge Astronomy Club || Red House || Virginia || P.O. Box 70 || https://www.BlueRidgeAstro.com || || ''✓''
|-
| Back Bay Amateur Astronomers || Virginia Beach || Virginia || P.O. Box 9877 || http://www.backbayastro.org/ || || ''✓''
|-
| Battle Point Astronomical Association || Bainbridge Island || Washington || P. O. Box 10914 || http://www.bpastro.org || || ''✓''
|-
| Whatcom Association of Celestial Observers || Ferndale || Washington || P. O. Box 1721 || https://www.whatcomastronomy.com/ || || ''✓''
|-
| Friends of Galileo || Longview || Washington || 1632 22nd Ave || || || ''✓''
|-
| Everett Astronomical Society || Mill Creek || Washington || P.O. Box 13272 || http://everettastro.org/ || || ''✓''
|-
| Island County Astronomical Society || Oak Harbor || Washington || PO Box 325 || http://www.icas-wa.org/ || || ''✓''
|-
| Seattle Astronomical Society || Seattle || Washington || P. O. Box 31746 || http://www.seattleastro.org || || ''✓''
|-
| Olympic Astronomical Society || SIlverdale || Washington || 9689 Clipper Pl NW || http://www.olympicastronomicalsociety.org || || ''✓''
|-
| Spokane Astronomical Society || Spokane || Washington || P. O. Box 8114 || http://www.spokaneastronomical.org/ || || ''✓''
|-
| Yakima Valley Astronomical Society || Yakima || Washington || 505 Santa Roza Dr #B || https://www.yakimavalleyastro.org/ || || ''✓''
|-
| Central Appalachian Astronomy Club || Bridgeport || West Virginia || 324 Bartlett Ave || http://www.caacwv.com || || ''✓''
|-
| Kanawha Valley Astronomical Society || Charleston || West Virginia || P.O. Box 2132 || https://www.kvas.org || || ''✓''
|-
| Chippewa Valley Astronomical Society || Eau Claire || Wisconsin || PO Box 1713 || http://www.cvastro.org || || ''✓''
|-
| Wehr Astronomical Society || Franklin || Wisconsin || 9701 W College Ave || || || ''✓''
|-
| Northern Cross Science Foundation || Grafton || Wisconsin || 2292 Ridgewood Road || http://www.ncsf.info || || ''✓''
|-
| Sheboygan Astronomical Society, Inc. || Kohler || Wisconsin || P.O. Box 292 || http://www.shebastro.org/ || || ''✓''
|-
| Iowa County Astronomers || Lone Rock || Wisconsin || 1014 Fairview Court || http://www.icastro.org/ || || ''✓''
|-
| Madison Astronomical Society || Madison || Wisconsin || P.O. Box 5585 || https://madisonastro.org/ || || ''✓''
|-
| Milwaukee Astronomical Society || New Berlin || Wisconsin || || http://www.milwaukeeastro.org/ || || ''✓''
|-
| Northeast Wisconsin Stargazers || Sherwood || Wisconsin || P.O. Box 267 || https://www.new-star.org || || ''✓''
|}

===United Kingdom===

*[http://www.astronomyclubs.co.uk/Clubs/Counties.aspx UK Clubs] This link provides a list of clubs by county in the UK.

===Europe===

*[https://eas.unige.ch/affiliates.jsp European Clubs] This link provides a list of clubs in Europe.

===Austrailia===

*[https://astronomy.org.au/amateur/amateur-societies/australia/ Austrailian Clubs] This link provides a list of clubs in Austrailia.

===Canada===

*[https://www.skynews.ca/resources/astronomy-clubs/ Canadian Clubs] This link provides a list of clubs in Canada.

Telescope Basics

2025-01-28T19:22:40Z

Jmh921: Created page with "(This is a work in progress) An optical telescope is an instrument designed to gather and focus light. It does this through the use of lenses, mirrors, or a combination of t..."

(This is a work in progress)

An optical telescope is an instrument designed to gather and focus light. It does this through the use of lenses, mirrors, or a combination of the two. Other kinds of telescopes exist to gather energy from other parts of the electromagnetic spectrum, including infrared, ultraviolet, radio, microwave, x-ray, and gamma ray energy. However, this wiki is primarily concerned with light, so unless otherwise stated, our discussion will be about light.

Main Page

2025-01-28T19:18:49Z

Jmh921:

=Welcome to John's Astronomy and Astrophotography Wiki=

This wiki was created as a repository for information about amateur astronomy and astrophotography. Everyone is welcome to look around and make use of the information here.

Unfortunately, due to severe spam and cyber-vandalism issues, I was forced to disable editing ability for un-approved users. If you would like the ability to add or edit content, please e-mail me [mailto:JohnHaynes@jmhastronomy.com?Subject=AstroWiki%20Account%20Upgrade%20Request here]. As long as I know you're a real human being and actually want to contribute, I'd be happy to elevate your account.

I'd really like to have more contributors and get more utilization from this site. As such, I encourage people to share the site and help develop it further (with elevated credentials as mentioned above). The more people contributing, the better this site will be.

==Helpful Starting Points==

Here is a [[Main Topic Index]]

And here is a [[List of topics that probably need to be discussed]]

==More Info==
This Wiki works very much like the [https://en.wikipedia.org/wiki/Main_Page Wikipedia]. It is a collaborative effort. The Wikipedia didn't get to its current point of almost 7 million articles (in English alone, there's millions also in other languages) through the work of a single person. People contribute to a wiki because they have information or experience in a topic and a desire to share what they have.

I'd also like to add a couple people with higher-level access who can help improve the site. In particular, people with experience with PHP development and especially those with experience configuring and maintaining a Media Wiki site are welcome to contact me if they're interested in helping manage the site.

==Wiki Stuff==

This site uses MediaWiki, the same software used for the [https://en.wikipedia.org/wiki/Main_Page Wikipedia].

Consult the [https://www.mediawiki.org/wiki/Special:MyLanguage/Help:Contents User's Guide] for information on using the wiki software.

There are a lot of tutorials online for using MediaWiki. [https://www.mediawiki.org/wiki/Manual:FAQ#Basic_usage Here's a great start to the basics of creating and editing wiki pages].

==Some Additional Wiki Links==
* [https://www.mediawiki.org/wiki/Special:MyLanguage/Manual:Configuration_settings Configuration settings list]
* [https://www.mediawiki.org/wiki/Special:MyLanguage/Manual:FAQ MediaWiki FAQ]
* [https://lists.wikimedia.org/mailman/listinfo/mediawiki-announce MediaWiki release mailing list]
* [https://www.mediawiki.org/wiki/Special:MyLanguage/Localisation#Translation_resources Localize MediaWiki for your language]
* [https://www.mediawiki.org/wiki/Special:MyLanguage/Manual:Combating_spam Learn how to combat spam on your wiki]

Recommended Observing Sites

2024-08-12T17:17:16Z

Jmh921: Created page with "This page lists recommended locations for amateur astronomers to go for observing. Some sites will be specifically geared for observing (e.g. club dark sites), and others wil..."

This page lists recommended locations for amateur astronomers to go for observing. Some sites will be specifically geared for observing (e.g. club dark sites), and others will be areas typically away from or shielded from city lights and recommended by fellow amateur astronomers.

Please note: some clubs do not like to publish/advertise the locations of their dark sites (e.g. to avoid theft or vandalism), so please do not add locations such as that without permission of the club officers (simply link to the club's webpage and note that the location is confidential).

= North America =

== United States ==
=== New Hampshire ===

==== YFOS ====
Youngs Farm Observing Site - the official dark site of the [[New Hampshire Astronomical Society]].

This site is on private land leased to the club by the owners of a farm in rural New Hampshire. The site has a roll-of roof observatory with a C14 on a Losmandy Titan mount, a warming hut, a chemical toilet, and one or two Dobsonian telescopes for member use. The site is open for member use most of the year, but may be closed due to weather-related issues, particularly during mud season in the late winter/early spring.

The site's skies are approximately 3 or 4 on the [https://en.wikipedia.org/wiki/Bortle_scale Bortle scale].

The specific location is confidential and available to club members only.

More information and photographs are available on the [http://www.nhastro.com/observatory.php NHAS] website.

==== Joppa Hill Fields ====

A site in Bedford, NH approximately 20 minutes (11-ish miles) from Manchester, NH. This site is frequently used by members of the [[New Hampshire Astronomical Society]]. The area used for observing is the dirt parking lot adjacent to the athletic fields. There are no streetlights of concern, but there is occasionally traffic on Joppa Hill Rd (and drivers frequently are using their high beams). The site's [https://en.wikipedia.org/wiki/Bortle_scale Bortle] rating is between 4 and 5.

Google Map link: [https://maps.app.goo.gl/ZTjEZGxT7XWgAfUT7 Joppa Hill Fields]

=== Texas ===

==== HAS Dark Site ====

This is the official observing site of the [[Houston Astronomical Society]] and lies approximately 90 minutes (depending on traffic) west of downtown Houston, between Columbus and Weimar. The site has approximately 5 acres of cleared space surrounded by trees and well-away from city lights. The site's skies are approximately 3 or 4 on the [https://en.wikipedia.org/wiki/Bortle_scale Bortle scale].

The site's facilities include the main observatory building with 3 permanently-mounted telescopes and a climate-controlled chart room, two bunk houses (one designated for women and families), a restroom with showers, and a shed containing 2 Dobsonian telescopes for club member use. here are also 38 concrete pads for setting up observing equipment. Power outlets are available and all pads are within 50' of an outlet.

The society rents out spaces for members to keep trailers/campers/RVs at the site as well as 12' square plots east and west of the observatory building for members to construct private observatory buildings.

The exact location of the site is confidential and requires club membership and the completion of an orientation and quiz to obtain the location and combination to the gate (which changes annually). It is open to members and guests year-round, though occasionally inaccessible due to flooding on the roads nearby.

Three discoveries have been made at the site, including a comet, a supernova, and the first visual observation of a meteor impact on the moon.

=== Vermont ===

==== Stellafane/Breezy Hill ====
Situated approximately 3 1/2 miles west of the town of Springfield, Vermont is the site run by the [https://stellafane.org Springfield Telescope Makers] on Breezy Hill which is the location of the annual [https://stellafane.org/convention/index.html Stellafane] convention. The site's [https://en.wikipedia.org/wiki/Bortle_scale Bortle] rating is approximately 4.

Access to the site is available to members of the Springfield Telescope Makers club and to Stellafane convention participants (during the convention).

Google Map link: [https://www.google.com/maps/@43.2776441,-72.5139267,876m/data=!3m1!1e3?entry=ttu Stellafane]

== Canada ==

== Europe ==

== Asia ==

== Australia ==

== South America ==

== Africa ==

Recommended Vendors

2023-11-30T15:47:51Z

Jmh921: /* Storefronts */

This page is to provide a list of recommended vendors for telescopes and other astronomy and astrophotography equipment and software.

I (John) launched the page with some links to vendors in the United States. If you have helpful information, particularly about vendors outside of the US or specific to your geographic location, please feel free to add them to this page. Also feel free to expand on other entries to add details (e.g. this site's prices tend to be higher than average, but they have better service, etc...). This is a group effort, so the more we put in, the more helpful this tool is to us all.

=United States=

==Nationwide Online Retailers==

====[https://www.astronomics.com/ Astronomics]====

Astronomics is another reliable supplier of equipment. Located in Norman, OK, they have a wide range of equipment, from low-end to high-end.

Their in-house brand is Astro-Tech, which is mostly made by [[Guan Sheng Optical Co|GSO]].

Astronomics is the primary sponsor of the [https://www.cloudynights.com Cloudy Nights] website.

====[https://www.highpointscientific.com/ High Point Scientific]====

Another reliable supplier of telescopes and astronomy equipment, based in Montague, NJ

Their in-house brand is Apertura, yet again made by [[Guan Sheng Optical Co|GSO]].

====[https://www.milehighastro.com/ Mile High Astronomy]====

Another reliable supplier of telescopes and astronomy equipment, based in Lakewood, CO, just outside of Denver. MHA ships nationwide by UPS.

====[https://optcorp.com/ Oceanside Photo and Telescope (OPT)]====

OPT has one of the largest selections online in the United States. Previously based in Oceanside, CA, they have recently moved to nearby Carlsbad. Their equipment ranges from low-end beginner stuff to some of the highest-end equipment available. They also have fairly knowledgeable staff. They are a reliable supplier of amateur astronomy equipment, if not the cheapest.

Their in-house brand is Third Planet Optics or TPO (which is, of course, OPT backwards). Most of the TPO stuff is made by [[Guan Sheng Optical Co|GSO]].

====[https://www.telescope.com/ Orion Telescopes & Binoculars]====

Orion is one of the top two vendors of telescopes; the other being Celestron. Orion's equipment is primarily made by Synta in mainland China; Celestron and SkyWatcher gear is made in the same factory. The quality of Orion's equipment is just as good as any of the other mass retailers (Celestron, SkyWatcher, Meade), which is quite high - - because it's all made in the same factory, and then painted different colors for the different vendors. And they have very good customer service as well.

However there are two big negative marks against Orion. One is that much Orion-branded astrogear is priced higher than equivalent equipment labelled with different brand names. There are a number of examples of this, including telescopes, eyepieces, and mounts.

A second is that Orion will not service or provide any support whatsoever to third-parties. To Orion, a third-party is anyone who hasn't bought Orion equipment from Orion itself, or an authorized dealer. In other words, if you buy used Orion gear from a fellow amateur astronomer, Orion will not lift a finger to help you with this gear in the slightest - if you need a part, if you need information. Nothing. It is the only major vendor that has this policy.

====[http://scopestuff.com/ ScopeStuff]====

This is a small web-based outfit selling lots of parts and accessories. One of their specialties is mounting hardware, including dovetail plates and tube rings as well as piggyback mounting hardware. They have great customer service and maintain their own database of details on a wide variety of scopes and what is needed for mounting them. If you don't now what you need, contact them and they can usually figure it out for you.

====[https://www.astronomy-mall.com/astro.parts.outlet/ Telescope Parts Outlet]====

This guy has a wide variety of used scopes and parts. He has a huge list of items available, and a lot of stuff isn't on the list. If you're missing a part or need a repair part, he's a great source, particularly for Orion, Celestron, and Meade.

====[https://smile.amazon.com/ref=smi_se_dshb_bk_smi Amazon.com]====

While Amazon does carry a large number of telescopes from various brands, caution is strongly recommended when purchasing via Amazon.

First, a lot of the products sold on Amazon are sold by other vendors through the Amazon interface. These vendors are known as resellers - they typically buy astronomical equipment from a reputable seller (listed here), and then sell it to you. While Amazon regulates this to some extent, if you're not buying FROM Amazon themselves, you may run into trouble with shipping and fulfillment as well as quality. Some buyers have reported issues with incomplete items (e.g. buying a Dob and either only getting the tube and not getting the base or only getting the base and not the tube). Others have had items damaged or lost in shipping. While Amazon typically works to make things right, often by refunding the purchase, this can be a serious hassle.

Second, most of the stuff carried on Amazon is lower-end equipment targeted at a poorly-educated retail market. In other words: lots of "department-store telescopes." A good example here is the Celestron PowerSeeker line (which is nearly entirely poor quality) is promoted and shows up prominently in search results.

Third, if you buy from a reseller, you have no warranty protection whatsoever. The vendors (Celestron, Orion, TeleVue, etc.) will not honor your purchase from a reseller. Therefore, you will have no recourse if there's anything wrong with your scope.

Lastly, the reviews on Amazon are often a very poor indicator. This is due to widespread abuse of the review system and outright fraudulent entries to boost search result positioning. This leads to lousy telescopes like the PowerSeeker 127eq receiving very high ratings and, with them, a prominent position in search results.

These problems, along with the lack of informed support from the vendor (most good vendors have informed and reasonably knowledgeable staff that can answer questions), make Amazon a very questionable source. This isn't to say you can't get decent equipment off Amazon, but that you should be extra-careful before ordering from them.

==Storefronts==

===California===

====Watsonville====

[https://www.telescope.com/content.jsp?pageName=StoreInformation&src=footer2 Orion Telescopes & Binoculars]

89 Hangar Way Watsonville, CA 95076, (831) 763-7000

====Cupertino====

[https://www.telescope.com/content.jsp?pageName=StoreInformation&src=footer2 Orion Telescopes & Binoculars]

10555 S. De Anza Blvd. Cupertino, CA 95014, (408) 255-8770

===Colorado===

====Denver====

[https://www.milehighastro.com Mile High Astronomy]

9797 West Colfax Avenue #3vv, Lakewood, CO, 80215, 877-279-5280

===Texas===

====Houston====

[https://www.landseaskyco.com Land Sea and Sky and Texas Nautical Repair]

1925A Richmond Ave. Houston, TX 77098, 713-364-0260

====San Antonio====

[https://www.analyticalsci.com/ Analytical Scientific]

11049 Bandera Road
San Antonio, TX 78250
210-684-7373

=Canada=

====[https://khanscope.com/ Khan Scope Center]====

====[https://www.ontariotelescope.com/ Ontario Telescopes]====

====[https://www.kwtelescope.com/ KW Telescope]====

====[https://www.all-startelescope.com/ All Star Telescope]====

====[https://focusscientific.com/ Focus Scientific]====

=European Union=

====[https://www.astroshop.eu/ Astroshop]====

A German online telescope and other optical instrument retailer, also operates a storefront in Landsberg am Lech, Germany. Ships anywhere in Europe, and to most of the world, where commercial parcel deliveries are available.

Has an in-house brand Omegon, mostly sources optics from GSO and Synta.

====[https://www.teleskop-express.de/shop/index.php/language/en Teleskop-Express]====

Another well-known German online telescope and other optical instrument retailer, located in Ebersberg, Germany. Will happily ship to pretty much anywhere in the world, for a reasonable price.

Has an in-house brand Teleskop-Service, or just TS.

=United Kingdom=

====[https://www.firstlightoptics.com/ First Light Optics]====

Probably the largest UK-based optical instrument retailer, but also will happily ship anywhere in the EU and to most of the world, operating from Exeter, Devon, UK.

====[https://www.orionoptics.co.uk/home.html Orion Optics UK]====

Not to be confused with the Orion Telescopes & Binoculars of the USA side of the world. This manufacturer and retailer mostly sells their own branded instruments, but also carries stock of other popular brands.

=Australia=

=India=

=Japan=

=South America=

Star Parties, Festivals, and Meetings

2023-04-22T19:10:23Z

Jmh921:

The following is a list of Star Parties and similar events
(Updated 4/22/2023)

=United States=
{| class="wikitable"
|-
! Party Name
! Starts
! Ends
! Location
! State
! Link
! Notes
|-
| Green Bank Star Quest
| 6/21/2023
| 6/24/2023
| Green Bank
| WV
| https://greenbankstarquest.org/
|
|-
| Almost Heaven Star Party
| 8/18/2023
| 8/22/2023
| Circleville
| WV
| https://www.ahsp.org/
|
|-
| Bootleg Spring Star Party
| 5/18/2023
| 5/21/2023
| Harmon
| IL
| http://bootlegastronomy.com/
|
|-
| Bootleg Fall Star Party
| 9/14/2023
| 9/17/2023
| Harmon
| IL
| http://bootlegastronomy.com/
|
|-
| Great Lakes Star Gaze
| 9/14/2023
| 9/17/2023
| Gladwin
| MI
| http://www.greatlakesstargaze.com/
|
|-
| Rocky Mountain Star Stare
| 6/14/2023
| 6/18/2023
| Gardner
| CO
| https://rmss.org/
|
|-
| Bryce Canyon Astronomy Festival
| 6/14/2023
| 6/17/2023
| Bryce Canyon Park
| UT
| https://www.brycecanyoncountry.com/events/bryce-canyon-astronomy-festival-2/
|
|-
| Idaho Star Party
| 9/15/2023
| 9/17/2023
| Bruneau Dunes Park
| ID
| https://boiseastro.org/event-4996997
|
|-
| Black Canyon Astronomy Festival
| 9/22/2023
| 9/24/2023
| Montrose
| CO
| https://www.nps.gov/blca/planyourvisit/astrofest.htm
|
|-
| Cherry Springs Star Party
| 6/15/2023
| 6/18/2023
| Coudersport
| PA
| https://sites.google.com/astrohbg.org/Cherry-Springs-Star-Party
|
|-
| Stellafane
| 8/17/2023
| 8/20/2023
| Springfield
| VT
| https://stellafane.org/
|
|-
| Acadia Night Sky Festival
| 9/21/2023
| 9/25/2023
| Bar Harbor
| ME
| https://www.acadianightskyfestival.org/
|
|-
| Stars Over Katahdin
| TBA
| TBA
| Millinocket
| ME
| https://www.friendsofkww.org/stars/
|
|-
| Astrophotography Conference
| 10/12/2023
| 10/15/2023
| Tupper Lake
| NY
| https://www.adirondackskycenter.org/events/Astrophotography-Conference-2023
|
|-
| Black Forest Star Party
| 9/15/2023
| 9/17/2023
| Potter County
| PA
| https://bfsp.org/
|
|-
| Oregon Star Party
| 7/18/2023
| 7/23/2023
| Prineville
| OR
| https://oregonstarparty.org/
|
|-
| Table Mountain Star Party
| 8/8/2023
| 8/12/2023
| Oroville
| WA
| http://www.tmspa.com/
|
|-
| Nebraska Star Party
| 7/16/2023
| 7/22/2023
| Valentine
| NE
| https://www.nebraskastarparty.org/
|
|-
| Okie-Tex Star Party
| 9/8/2023
| 9/16/2023
| Kenton
| OK
| http://www.okie-tex.com/
|
|-
| Dakota Nights Festival
| TBA
| TBA
| Medora
| ND
| https://www.nps.gov/thro/learn/nature/dakota-nights-festival.htm
|
|-
| Badlands Festival
| 7/14/2023
| 7/16/2023
| Rapid City
| SD
| https://www.nps.gov/thingstodo/badl-astronomy-festival.htm
|
|-
| Midsouth Stargaze
| 4/19/2023
| 4/22/2023
| French Camp
| MS
| https://rainwaterobservatory.org/events
|
|-
| Texas Star Party
| 5/14/2023
| 5/21/2023
| Fort Davis
| TX
| https://texasstarparty.org/
|
|-
| Orange Blossom Special
| 2/7/2024
| 2/11/2024
| Dade City
| FL
| https://www.stpeteastronomyclub.org/OBS/
|
|-
| Winter Star Party
| 2/5/2024
| 2/11/2024
| Scout Key
| FL
| https://www.scas.org/winter-star-party/
|
|-
| Death Valley Dark Sky Festival
| 2/10/2023
| 2/12/2023
| Death Valley
| CA
| https://www.nps.gov/deva/planyourvisit/death-valley-dark-sky-festival.htm
|
|-
| California Dark Sky Festival
| 10/12/2023
| 10/15/2023
| Panamint Valley
| CA
| https://www.easternsierraobservatory.com/california-dark-sky-festival
|
|-
| Grand Canyon Star Party
| 6/10/2023
| 6/17/2023
| Grand Canyon Park
| AZ
| https://www.nps.gov/grca/planyourvisit/grand-canyon-star-party.htm
|
|-
| Golden State Star Party
| 6/14/2023
| 6/18/2023
| Bieber
| CA
| http://goldenstatestarparty.org/
|
|-
| Advanced Imaging Conference
| TBA
| TBA
| San Jose
| CA
| https://www.advancedimagingconference.com/
|
|-
| Night Sky Festival
| 10/13/2023
| 10/14/2023
| Twentynine Palms
| CA
| https://www.skysthelimit29.org/night-sky-festival.html
|
|}

Star Parties, Festivals, and Meetings

2023-04-22T19:05:47Z

Jmh921: Created page with "The following is a list of Star Parties and similar events in the United States (Updated 4/22/2023) {| class="wikitable" |- ! Party Name ! Starts ! Ends ! Location !..."

The following is a list of Star Parties and similar events in the United States

(Updated 4/22/2023)

{| class="wikitable"
|-
! Party Name
! Starts
! Ends
! Location
! State
! Region
! Link
! Notes
|-
| Green Bank Star Quest
| 6/21/2023
| 6/24/2023
| Green Bank
| WV
| East
| https://greenbankstarquest.org/
|
|-
| Almost Heaven Star Party
| 8/18/2023
| 8/22/2023
| Circleville
| WV
| East
| https://www.ahsp.org/
|
|-
| Bootleg Spring Star Party
| 5/18/2023
| 5/21/2023
| Harmon
| IL
| Midwest
| http://bootlegastronomy.com/
|
|-
| Bootleg Fall Star Party
| 9/14/2023
| 9/17/2023
| Harmon
| IL
| Midwest
| http://bootlegastronomy.com/
|
|-
| Great Lakes Star Gaze
| 9/14/2023
| 9/17/2023
| Gladwin
| MI
| Midwest
| http://www.greatlakesstargaze.com/
|
|-
| Rocky Mountain Star Stare
| 6/14/2023
| 6/18/2023
| Gardner
| CO
| Mountains
| https://rmss.org/
|
|-
| Bryce Canyon Astronomy Festival
| 6/14/2023
| 6/17/2023
| Bryce Canyon Park
| UT
| Mountains
| https://www.brycecanyoncountry.com/events/bryce-canyon-astronomy-festival-2/
|
|-
| Idaho Star Party
| 9/15/2023
| 9/17/2023
| Bruneau Dunes Park
| ID
| Mountains
| https://boiseastro.org/event-4996997
|
|-
| Black Canyon Astronomy Festival
| 9/22/2023
| 9/24/2023
| Montrose
| CO
| Mountains
| https://www.nps.gov/blca/planyourvisit/astrofest.htm
|
|-
| Cherry Springs Star Party
| 6/15/2023
| 6/18/2023
| Coudersport
| PA
| Northeast
| https://sites.google.com/astrohbg.org/Cherry-Springs-Star-Party
|
|-
| Stellafane
| 8/17/2023
| 8/20/2023
| Springfield
| VT
| Northeast
| https://stellafane.org/
|
|-
| Acadia Night Sky Festival
| 9/21/2023
| 9/25/2023
| Bar Harbor
| ME
| Northeast
| https://www.acadianightskyfestival.org/
|
|-
| Stars Over Katahdin
| TBA
| TBA
| Millinocket
| ME
| Northeast
| https://www.friendsofkww.org/stars/
|
|-
| Astrophotography Conference
| 10/12/2023
| 10/15/2023
| Tupper Lake
| NY
| Northeast
| https://www.adirondackskycenter.org/events/Astrophotography-Conference-2023
|
|-
| Black Forest Star Party
| 9/15/2023
| 9/17/2023
| Potter County
| PA
| Northeast
| https://bfsp.org/
|
|-
| Oregon Star Party
| 7/18/2023
| 7/23/2023
| Prineville
| OR
| Northwest
| https://oregonstarparty.org/
|
|-
| Table Mountain Star Party
| 8/8/2023
| 8/12/2023
| Oroville
| WA
| Northwest
| http://www.tmspa.com/
|
|-
| Nebraska Star Party
| 7/16/2023
| 7/22/2023
| Valentine
| NE
| Plains
| https://www.nebraskastarparty.org/
|
|-
| Okie-Tex Star Party
| 9/8/2023
| 9/16/2023
| Kenton
| OK
| Plains
| http://www.okie-tex.com/
|
|-
| Dakota Nights Festival
| TBA
| TBA
| Medora
| ND
| Plains
| https://www.nps.gov/thro/learn/nature/dakota-nights-festival.htm
|
|-
| Badlands Festival
| 7/14/2023
| 7/16/2023
| Rapid City
| SD
| Plains
| https://www.nps.gov/thingstodo/badl-astronomy-festival.htm
|
|-
| Midsouth Stargaze
| 4/19/2023
| 4/22/2023
| French Camp
| MS
| South
| https://rainwaterobservatory.org/events
|
|-
| Texas Star Party
| 5/14/2023
| 5/21/2023
| Fort Davis
| TX
| South
| https://texasstarparty.org/
|
|-
| Orange Blossom Special
| 2/7/2024
| 2/11/2024
| Dade City
| FL
| Southeast
| https://www.stpeteastronomyclub.org/OBS/
|
|-
| Winter Star Party
| 2/5/2024
| 2/11/2024
| Scout Key
| FL
| Southeast
| https://www.scas.org/winter-star-party/
|
|-
| Death Valley Dark Sky Festival
| 2/10/2023
| 2/12/2023
| Death Valley
| CA
| Southwest
| https://www.nps.gov/deva/planyourvisit/death-valley-dark-sky-festival.htm
|
|-
| California Dark Sky Festival
| 10/12/2023
| 10/15/2023
| Panamint Valley
| CA
| Southwest
| https://www.easternsierraobservatory.com/california-dark-sky-festival
|
|-
| Grand Canyon Star Party
| 6/10/2023
| 6/17/2023
| Grand Canyon Park
| AZ
| Southwest
| https://www.nps.gov/grca/planyourvisit/grand-canyon-star-party.htm
|
|-
| Golden State Star Party
| 6/14/2023
| 6/18/2023
| Bieber
| CA
| Southwest
| http://goldenstatestarparty.org/
|
|-
| Advanced Imaging Conference
| TBA
| TBA
| San Jose
| CA
| Southwest
| https://www.advancedimagingconference.com/
|
|-
| Night Sky Festival
| 10/13/2023
| 10/14/2023
| Twentynine Palms
| CA
| Southwest
| https://www.skysthelimit29.org/night-sky-festival.html
|
|}

Chromatic aberration

2022-05-26T01:05:07Z

Jmh921:

Chromatic Aberration is an optical aberration that occurs when light passes through a medium such as a glass lens which causes different wavelengths (colors) of light to focus at different focal lengths and degrades the image.

''this page is a work in progress''

==Refraction==

Refraction is the bending of light by passing it through a medium. While the speed of light in a vacuum is approximately 300,000 kilometers per second, when light passes through a medium such as air, water, or glass, it is slowed. Different wavelengths of light, which are perceived by human eyes as colors, are affected to differing amounts. Light with shorter wavelengths, which appears bluer, is bent to a greater degree than is light with a longer, redder, wavelength.

[[File:Light dispersion conceptual waves.gif|thumb|Light passing through a typical prism.]]

The same phenomenon is what makes a prism split white light into separate colors also causes chromatic aberration. In the example image to the right, as white light passes through the glass prism, the various colors of light are slowed at varying rates, causing them to bend, or refract.

In a typical glass [[convex]] lens, the glass is thicker in the center and thinner along the edges of the lens. When light passes through the glass, it is slowed down. Because there is less glass on the edges, that light is slowed less than the light closer to the center. This causes the path of all wavelengths of light to bent toward the center axis of the lens. Where the light rays all converge is the focal point.

But because red light is less affected than blue light, the focal point for red light will be further from the lens than it will be for blue light as shown here:

[[File:Chromatic aberration lens diagram.svg|Chromatic aberration lens diagram]]

The visible result is that objects in the view tend to be blurred somewhat. This is most easily noticeable in images of objects with distinct edges, particularly if there is also a significant contrast between colors or light and dark areas of the image.

[[File:Chromatic aberration (comparison).jpg|thumb|Above: an image without chromatic aberration, below the same image with chromatic aberration apparent.]]

Telescopes which use mirrors instead of lenses to gather and focus light are not subject to chromatic aberration as the light does not pass through glass. When an eyepiece is used, there may be some chromatic aberration caused by the eyepiece, though this is typically less noticeable.

The problem is exacerbated by the thickness of the glass the light is passing through. Lenses with a shorter [[focal ratio]] have a more distinct curvature to them, while longer focal ratios have less significant curvature. This means that in lenses with shorter focal ratios, the difference between the center of the lens and the edges is much greater than that of shorter focal ratio lenses. As such, the amount of slowing of the light is more varied in a shorter focal length lens, which increases the effect of chromatic aberration. For this reason, most simple single-lens refractors tend to have long focal ratios to reduce the appearance of chromatic aberration.

==Reducing Chromatic Aberration==

A mentioned previously, longer focal ratios reduce the appearance of the aberration, bringing the various focal points of different wavelengths of light closer together. This was the earliest way of dealing with the problem.

The problem chiefly applies to [[Refractor|refracting telescopes]]. In

==References==
<references group=""/>

Chromatic aberration

2022-05-25T22:37:01Z

Jmh921:

Helpful Links

2022-02-17T02:53:12Z

Jmh921: /* Helpful Astronomy Links */

This is a list of links I have compiled for various helpful websites. They are in no specific order.

They should all open in a new window/tab.

Please feel to let me know if there are links that need to be added.

==Helpful Astronomy Links==

{| class="wikitable sortable"
! style="background-color:#000000; color:#ffffff;" | ID
! style="background-color:#000000; color:#ffffff;" | Link
! style="background-color:#000000; color:#ffffff;" | Link Notes
! style="background-color:#000000; color:#ffffff;" | Category
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|1
|style="font-size:9pt;"|[http://support.itelescope.net/support/solutions/articles/232433-fov-chart iTelescope.net FOV Chart]
|style="font-size:8pt;"|This is a diagram showing the FOV footprints for various iTelescope instruments.
|style="font-size:9pt;"|Reference
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|2
|style="font-size:9pt;"|[http://astronomy.tools/calculators/field_of_view/ Astronomy Tools FOV Caluclator]
|style="font-size:8pt;"|This is a field of view calculator
|style="font-size:9pt;"|Reference
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|3
|style="font-size:9pt;"|[https://www.lightpollutionmap.info Light Pollution Map]
|style="font-size:8pt;"|This is one of several light pollution map sites
|style="font-size:9pt;"|Reference
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|4
|style="font-size:9pt;"|[http://astronomy.tools Astronomy Tools]
|style="font-size:8pt;"|This site has several helpful tools, including a FOV calculator
|style="font-size:9pt;"|Reference
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|5
|style="font-size:9pt;"|[http://www.moongiant.com/calendar/ Moon Phase Calendar]
|style="font-size:8pt;"|This is a moon phase calendar
|style="font-size:9pt;"|Reference
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|6
|style="font-size:9pt;"|[https://www.timeanddate.com/moon/usa/houston Sun/Moon Rise Set Times]
|style="font-size:8pt;"|This site gives sun and moon rise and set times
|style="font-size:9pt;"|Reference
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|7
|style="font-size:9pt;"|[http://astrometry.net/ Astrometry]
|style="font-size:8pt;"|Plate Solving
|style="font-size:9pt;"|Tools and Calculators
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|8
|style="font-size:9pt;"|[http://www.astromax.com/ Astromax]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Club
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|9
|style="font-size:9pt;"|[http://www.kellysky.net kellysky]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Personal Site
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|10
|style="font-size:9pt;"|[http://www.reinervogel.net/index_e.html?/Plattform/Plattform_e.html EQ platforms]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Reference
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|11
|style="font-size:9pt;"|[https://apod.nasa.gov/apod/astropix.html APOD]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Magazine
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|12
|style="font-size:9pt;"|[https://astrodonimaging.com/tutorials/ Astrodon Imaging]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Reference
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|13
|style="font-size:9pt;"|[https://astromart.com AstroMart]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Retailer
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|14
|style="font-size:9pt;"|[https://avila.star-shine.ch/astro/messiercharts/messierTelrad.htm Messier Telrad Charts]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Reference
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|15
|style="font-size:9pt;"|[https://bf-astro.com/starRepair.htm Star Repair tutorial]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Reference
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|16
|style="font-size:9pt;"|[https://bollerandchivens.com/ Boller And Chivens (Historical scopes)]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Historical
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|17
|style="font-size:9pt;"|[https://cleardarksky.com ClearDarkSky]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Weather
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|18
|style="font-size:9pt;"|[https://clearoutside.com ClearOutside]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Weather
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|19
|style="font-size:9pt;"|[https://diffractionlimited.com SBIG]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Manufacturer
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|20
|style="font-size:9pt;"|[https://lumicon.com Lumicon]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Manufacturer
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|21
|style="font-size:9pt;"|[https://mesu-optics.nl MESU]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Manufacturer
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|22
|style="font-size:9pt;"|[https://openphdguiding.org/ PHD2]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Software
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|23
|style="font-size:9pt;"|[https://optcorp.com OPT]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Retailer
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|24
|style="font-size:9pt;"|[https://starizona.com Starizona]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Retailer
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|25
|style="font-size:9pt;"|[https://telecalc.tk/ Dankgum's Telescope Calculator]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Tools and Calculators
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|26
|style="font-size:9pt;"|[https://telescope.org Open University Telescopes]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Online Telescopes
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|27
|style="font-size:9pt;"|[https://www.admaccessories.com ADM Accessories]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Manufacturer
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|28
|style="font-size:9pt;"|[https://www.artsnova.com/Photoshop_Astronomy.html Photoshop Tutorials]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Reference
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|29
|style="font-size:9pt;"|[https://www.astronomics.com Astronomics]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Retailer
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|30
|style="font-size:9pt;"|[https://www.astronomyhouston.org Houston Astronomical Society]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Club
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|31
|style="font-size:9pt;"|[https://www.astronomy-mall.com/astro.parts.outlet/ Astro Parts Outlet]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Retailer
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|32
|style="font-size:9pt;"|[https://www.astropublishing.com AstroPublishing]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Magazine
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|33
|style="font-size:9pt;"|[https://www.bbastrodesigns.com/tm.html bbastrodesigns]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Amateur Telescope Making (ATM)
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|34
|style="font-size:9pt;"|[https://www.bisque.com/sc/ Software Bisque]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Manufacturer
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|35
|style="font-size:9pt;"|[https://www.bobatkins.com/photography/technical/field_of_view.html fov technical info]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Reference
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|36
|style="font-size:9pt;"|[https://www.celestron.com Celestron]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Manufacturer
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|37
|style="font-size:9pt;"|[https://www.cloudynights.com Cloudy Nights]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Social Media
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|38
|style="font-size:9pt;"|[https://www.digicamdb.com digicam db]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Astrophotography-Related
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|39
|style="font-size:9pt;"|[https://www.highpointscientific.com High Point Scientific]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Retailer
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|40
|style="font-size:9pt;"|[https://www.itelescope.net iTelescope]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Online Telescopes
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|41
|style="font-size:9pt;"|[https://www.jshine.net/astronomy/dark_sky/ dark sky finder]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Light Pollution
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|42
|style="font-size:9pt;"|[https://www.meade.com Meade]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Manufacturer
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|43
|style="font-size:9pt;"|[https://www.minorplanetcenter.net/iau/mpc.html Minor Planet Center]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Reference
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|44
|style="font-size:9pt;"|[https://www.moonconnection.com/moon_phases_calendar.phtml Moon Phase Calendar]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Reference
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|45
|style="font-size:9pt;"|[https://www.sensorgen.info/ SensorGen]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Astrophotography-Related
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|46
|style="font-size:9pt;"|[https://www.skyandtelescope.com/ Sky and Telescope]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Magazine
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|47
|style="font-size:9pt;"|[https://www.skyatnightmagazine.com Sky At Night Magazine]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Magazine
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|48
|style="font-size:9pt;"|[https://www.skyatnightmagazine.com/astronomy-field-view-calculator Sky At Night FOV]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Tools and Calculators
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|49
|style="font-size:9pt;"|[https://www.stark-labs.com/ Stark Labs]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Software
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|50
|style="font-size:9pt;"|[https://www.swindonstargazers.com/beginners/eyepieces.htm Swindon Stargazers about Eyepieces]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Reference
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|51
|style="font-size:9pt;"|[https://www.telescope.com Orion]
|style="font-size:8pt;"|(Needs description)
|style="font-size:9pt;"|Manufacturer
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|52
|style="font-size:9pt;"|[http://www.robertreeves.com Robert Reeves Lunar Imaging Site]
|style="font-size:8pt;"|Robert Reeves's site for lunar and planeting images along with tutorials.
|style="font-size:9pt;"|Personal Site
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|53
|style="font-size:9pt;"|[https://darkskies.space/ _darkSkies Astrophotography]
|style="font-size:8pt;"|This is the personal site of a guy in Germany who does some pretty good AP and has some very helpful information for beginners.
|style="font-size:9pt;"|Personal Site
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|54
|style="font-size:9pt;"|[http://sas-sky.org/wp-content/uploads/2011/09/SAS-The-Use-of-Astronomical-Filters1.pdf Sangamon Astronomical Society Filter Advice]
|style="font-size:8pt;"|An astronomy club in Springfield, Illinos offers filter advice.
|style="font-size:9pt;"|Informational
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|55
|style="font-size:9pt;"|[https://agenaastro.com/choosing-a-color-planetary-filter.html Agena Astro Planetary Filter Info]
|style="font-size:8pt;"|This site shows some recommendations for color filter usage when viewing planets.
|style="font-size:9pt;"|Informational
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|56
|style="font-size:9pt;"|[http://hosting.astro.cornell.edu/academics/courses/astro201/diff_limit.htm Light Diffraction Formula]
|style="font-size:8pt;"|A page from a Cornell University astronomy course website concerning light diffraction.
|style="font-size:9pt;"|Reference
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|57
|style="font-size:9pt;"|[http://www.astro.shoregalaxy.com/dslr_calc.htm Ray Shore's Calculator for DSLR Astrophotography]
|style="font-size:8pt;"|A page with some DSLR AP calculations, including effective magnification.
|style="font-size:9pt;"|Reference
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|58
|style="font-size:9pt;"|[https://www.reddit.com/r/telescopes/comments/7o18zb/what_i_learned_about_observing_in_2017/ Observing and Exit Pupil]
|style="font-size:8pt;"|Reddit Post by PhpDevster about Observing and Exit Pupil
|style="font-size:9pt;"|Articles & Topic Posts
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|59
|style="font-size:9pt;"|[https://medium.com/@phpdevster/how-telescope-aperture-affects-your-view-24507147d7fc How Telescope Aperture Affects The View]
|style="font-size:8pt;"|Medium.com Post by PhpDevster about Exit Pupil
|style="font-size:9pt;"|Articles & Topic Posts
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|60
|style="font-size:9pt;"|[https://www.darkframeoptics.com/blog/mount-performance-charts-1 EQ Mount Performance Charts]
|style="font-size:8pt;"|A discussion of periodic error performance of several equatorial mounts.
|style="font-size:9pt;"|Reference
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|61
|style="font-size:9pt;"|[http://lambermont.dyndns.org/astro/pe.html An astrophotography mount performance overview]
|style="font-size:8pt;"|Another discussion of periodic error performance of several equatorial mounts.
|style="font-size:9pt;"|Reference
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|62
|style="font-size:9pt;"|[http://lambermont.dyndns.org/astro/ Hans Lambermont's AP links and images]
|style="font-size:8pt;"|A bunch of AP information and images from the personal site of someone in the Netherlands named Hans Labermont.
|style="font-size:9pt;"|Reference
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|63
|style="font-size:9pt;"|[https://www.scantips.com/lights/fieldofview.html Scantips FOV calculator]
|style="font-size:8pt;"|A reference site with an FOV calculator - more conventional photography oriented than AP.
|style="font-size:9pt;"|Astrophotography-Related
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|64
|style="font-size:9pt;"|[http://clarkvision.com/articles//digital.sensor.performance.summary/index.html ClarkVision Sensor Data]
|style="font-size:8pt;"|Details on imaging sensor performance
|style="font-size:9pt;"|Astrophotography-Related
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|65
|style="font-size:9pt;"|[https://magiclantern.fm/ Magic Lantern Firmware]
|style="font-size:8pt;"|Firmware Mods for DSLRs
|style="font-size:9pt;"|Astrophotography-Related
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|66
|style="font-size:9pt;"|[https://www.ideiki.com/astro/EOS.aspx Camera Control EOS Details]
|style="font-size:8pt;"|Details on imaging sensor performance
|style="font-size:9pt;"|Astrophotography-Related
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|67
|style="font-size:9pt;"|[https://docs.google.com/spreadsheets/d/1Og7jDK4t4-hd4AgezX8PG8Wav-wBHXbDd4YJeymx6yg/edit?fbclid=IwAR3XO55Qb6U5daBYXv9tmzodUv4mrVaivZH2phTa0YWvspf4UXekl7QvY1M#gid=215547869 iTelescope.net Telescope Details]
|style="font-size:8pt;"|A list of the iTelescope.net instruments including the telescope types, apertures, focal lengths, camera details and mounts.
|style="font-size:9pt;"|Astrophotography-Related
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|68
|style="font-size:9pt;"|[https://skyandtelescope.org/observing/stargazers-corner/simple-formulas-for-the-telescope-owner/#:~:text=Focal%20Ratio%20(f%2Fstop)&text=For%20example%2C%20a%20telescope%20with%20a%20focal%20length%20of%201000mm,900%20mm%20focal%20length%2C%20telescope. Simple Formulas for the Telescope Owner (Sky and Telescope)]
|style="font-size:8pt;"|A list of common formulae for amateur astronomy.
|style="font-size:9pt;"|Astrophotography-Related
|-
|style="background-color:#008000; color:#FFFFFF; style="font-size:8pt;"|68
|style="font-size:9pt;"|[https://www.californiaskys.com/blog/category/eaa-for-beginners EAA With an SCT on an Alt-Az Mount]
|style="font-size:8pt;"|This is a good primer on EAA for those just getting started.
|style="font-size:9pt;"|[[EAA]]
|}

EAA

2022-02-17T02:48:07Z

Jmh921:

EAA is short for Electronically Assisted Astronomy. EAA is a subset of astrophotography, but more geared for live-viewing as opposed to capturing images to be printed or displayed on websites.

(This article needs a lot more info)

Here's a helpful link for those just getting started: [https://www.californiaskys.com/blog/category/eaa-for-beginners California Skys: EAA For Beginners]

EAA

2022-02-17T02:06:50Z

Jmh921: Created page with "EAA is short for Electronically Assisted Astronomy. EAA is a subset of astrophotography, but more geared for live-viewing as opposed to capturing images to be printed or disp..."

Helpful Links

2020-06-26T16:31:05Z

Jmh921:

Helpful Links

2020-06-26T16:25:55Z

Jmh921: /* Helpful Astronomy Links */

Digital Astrophotography

2020-04-02T14:09:37Z

Jmh921:

''DRAFT''

----

Most astrophotography is now done using digital imaging equipment and techniques. While there are still some people who do astrophotography on film, most astrophotographers prefer the advantages digital imaging offers.

It helps to understand the basics of digital imaging, how cameras work, how color is captured, and the advantages that digital imaging offers over film.

=Advantages=

One of the key advantages is the fact that digital imaging does not require film, and, therefore, photographers can capture an unlimited number of images and not need to use chemicals to process them. Processing film requires specific equipment, chemicals, and techniques that the average person does not possess. Most people have a computer or access to one, and digital cameras have far surpassed the availability of film cameras.

With film, if you don't have the development equipment and chemicals, you could send the film out for processing, but few processing companies would have the expertise needed to process the images properly to get good prints. Most astrophotographers had to do the work themselves.

With digital imaging, image files are saved as a set of numeric values, and this affords us the opportunity to use mathematics to transform and enhance the data. This above all else changes the game for amateur astrophotography.

=Image Sensors=

And image sensor in a digital camera is an electronic component that senses light and quantifies it. Fundamentally, an image sensor is a photon counter - counting photons, which are the smallest units of light energy, that reach it.

There are two main types of image sensors: Charge-Coupled Devices, or CCD, and Complementary Metal-Oxide Semiconductors (CMOS). Each has certain advantages and disadvantages, but the way they function is similar. The material of the sensor is a type of semiconductor material. One key property of semiconductors is the ability to act as a switch In the case of image sensors, when a photon of light reaches the surface of the sensor, it causes the charge on that sensor element (i.e. pixel) to increase slightly. Every photon that reaches it will have the same effect. When a picture is taken, the sensor is exposed to the light source, and then, when done, the level of charge on the element is counted and recorded.

An image sensor in a camera is essentially a collection of individual elements like this, known as pixels, each of a given size, arrayed in a grid. When the picture is taken, the processing circuit on the sensor reads each pixel value and records it in a data structure which is then saved to a disk or removable medium as a file.

It's worth noting here that the image sensor does not detect color. No digital camera image sensor that I'm aware of detects color, at least none in regular production cameras. We will circle back to color in a bit. For the moment, what's important is that the sensor simply quantifies the amount of light detected by measuring the charge on the pixel which is increased each time a photon of light interacts with it.

==Short Discussion of Light==
Stepping back a moment, it helps here to understand a few things about light. First, it is well understood that light behaves both as a particle and a wave. There has been a lot of scientific study devoted to this and we won't delve into that. But we will discuss both natures briefly.

As mentioned before, a photon is the smallest unit of light. When a photon interacts with the light-sensitive material of the image sensor, the material acts like a switch to allow the charge to flow. Each photon allows a small amount of energy to flow into the pixel, and at the end of the exposure, the total charge on the pixel is read.

But looking at light as a wave, one of the properties of waves is wavelength: the distance between peaks of a wave. What we call "light" is just a subset of the entire spectrum of electromagnetic radiation. Radio waves are another form. As are x-rays and gamma rays. There are two common ways of measuring electromagnetic radiation: frequency and wavelength. Generally speaking, frequency and wavelength measure the same thing in different ways. Waves are often diagrammed on a graph:

[[File:SimpleWave.png|center|500px|Basic anatomy of an electromagnetic wave.]]

Frequency is based on cycles, which refers to a single full peak and trough of a wave. Frequency is the number of cycles that occur per second and is measured using the unit Hertz. 1 Hertz is one cycle per second. 1 Kilo Hertz, or KHz, is 1,000 cycles per second. FM radio runs from about 88 to 108 MHz, or Mega Hertz (1 million cycles per second). Wavelength is the measure (in metric units) of the distance between peaks of a wave. If you look at 88 MHz, if there are 88 million cycles per second, and light moves at a speed of 299,792,458 meters per second, then the wavelength must be about 3.4 meters.

When we start getting up into the higher frequencies of electromagnetic radiation, the frequency numbers get huge. Light on the blue-end of the visible light spectrum has a frequency around 750,000,000,000,000 Hz, or 750 Terra Hertz(THz). Conversely, while the frequency numbers get higher, the wavelengths get smaller. If you calculate the space between wave peaks for 750 THz you end up with a very small number: about 400 nanometers (nm) (or 400 billionths of a meter). Generally speaking, when referring to light and other small wavelength electromagnetic radiation, wavelength is used.

Human vision is sensitive to a band of wavelengths between about 400 nm and 700 nm, give or take a little. We experience the differences in those wavelengths as different colors. For example, what we call blue is found at the shorter end of the wavelength spectrum, close to 400 nm. Longer wavelengths nearer the 700 nm end are redder. Beyond 700 nm is the infra-red range, while under 400 is the ultraviolet range.

==Sensors and Wavelength==

As mentioned previously, image sensors don't measure color. A typical image sensor is sensitive for a wide range of wavelengths, usually somewhat beyond human vision. For example, most digital cameras sold for conventional photography (i.e. not astrophotography or other scientific specialty use) have a built-in filter that cuts down the longer wavelength light that reaches the sensor. This is done to improve the color balance and help it better-match human vision. Without such a filter, the sensor can usually capture light beyond 700 nm, somewhat into the infra-red range. In fact, in 1998, Sony released a video camera designed with a "night-vision" feature which captured infra-red. Unfortunately, this had the accidental side-effect of seeing through some clothing, so the camera was quickly re-configured to prevent that. It's also interesting to note that most digital cameras can see the infrared light put off by most remote controls for home television and audio equipment. If you were to hold up your cell phone camera and face the remote control at the camera, when you press a button on the remote, you are likely to see it light up through the camera, but not with your eyes, which are not sensitive to those wavelengths.

While a sensor isn't specific to a given color of light, it will only be sensitive over a certain range, and not equally to all wavelengths.

Digital Astrophotography

2020-03-31T16:29:04Z

Jmh921:

File:SimpleWave.png

2020-03-31T16:15:44Z

Jmh921: Jmh921 uploaded a new version of File:SimpleWave.png

== Summary ==
A simple diagram of a wave
== Licensing ==
{{Personal}}

File:SimpleWave.png

2020-03-30T18:07:16Z

Jmh921: A simple diagram of a wave

== Summary ==
A simple diagram of a wave
== Licensing ==
{{Personal}}

Digital Astrophotography

2020-03-30T18:06:18Z

Jmh921:

Digital Astrophotography

2020-03-30T15:41:31Z

Jmh921: Created page with " ''DRAFT'' ---- Most astrophotography is now done using digital imaging equipment and techniques. While there are still some people who do astrophotography on film, most..."

Main Page

2020-03-24T18:40:12Z

Jmh921:

Welcome to John's Astronomy and Astrophotography Wiki

I have created this site as a repository for information on astronomy and astrophotography. Feel free to look around.

Here is a [[Main Topic Index]]

And here is a [[List of topics that probably need to be discussed]]

There isn't much content as yet. I hope this will change soon.

This Wiki works very much like the [https://en.wikipedia.org/wiki/Main_Page Wikipedia]. It is a collaborative effort. The Wikipedia didn't get to its current point of over 6 million articles (in English alone, there's millions also in other languages) through the work of a single person. People contribute to a wiki because they have information or experience in a topic and a desire to share what they have.

If you're interested, please feel free to create an account and join the team.

I have had to lock-down editing due to spam and cyber vandalism. You can still create an account, but if you want access to creating and editing pages, I will need to upgrade you. I'm happy to do so, as long as I know you're a real human being, not a bot, and not some idiot just wanting to post spam. Just [mailto:johnhaynes@jmhastronomy.com?Subject=AstroWiki%20Account%20Creation%20Assistance e-mail me] and I'll upgrade you.

I'd also like to add a couple people with higher-level access who can help improve the site. In particular, people with experience with PHP development and especially those with experience configuring and maintaining a Media Wiki site are welcome to contact me if they're interested in helping manage the site.

This site uses MediaWiki, the same software used for the [https://en.wikipedia.org/wiki/Main_Page Wikipedia].

Consult the [https://www.mediawiki.org/wiki/Special:MyLanguage/Help:Contents User's Guide] for information on using the wiki software.

There are a lot of tutorials online for using MediaWiki. [https://www.mediawiki.org/wiki/Manual:FAQ#Basic_usage Here's a great start to the basics of creating and editing wiki pages].

== Getting started ==
* [https://www.mediawiki.org/wiki/Special:MyLanguage/Manual:Configuration_settings Configuration settings list]
* [https://www.mediawiki.org/wiki/Special:MyLanguage/Manual:FAQ MediaWiki FAQ]
* [https://lists.wikimedia.org/mailman/listinfo/mediawiki-announce MediaWiki release mailing list]
* [https://www.mediawiki.org/wiki/Special:MyLanguage/Localisation#Translation_resources Localize MediaWiki for your language]
* [https://www.mediawiki.org/wiki/Special:MyLanguage/Manual:Combating_spam Learn how to combat spam on your wiki]

Exit Pupil

2020-02-04T18:10:10Z

Jmh921:

==Overview==
An eyepiece's primary purpose is to magnify the view in a telescope, but how much magnification it provides, and the size of the aperture of the telescope, can influence how bright the view is. High magnification in a smaller aperture will result in a very dim view. Conversely, lower magnification will produce a brighter view.

The brightness of the view is best described by a property known as exit pupil. While strictly speaking, exit pupil is the diameter of a virtual aperture produced by the eyepiece in the telescope, it is easier to think of it as the size of the "beam" of light that leaves the eyepiece and enters the eye. The larger the exit pupil, the brighter the view will be. The smaller the exit pupil, the dimmer the view will be.

The useful size of the exit pupil is typically between 0.5mm and 7mm, though it varies from situation to situation. The upper size limit depends on how widely one's own pupils dilate. The average for most young adults is around 7mm. If the exit pupil exceeds this size, it means not all light from the telescope is entering the observer's eye, which reduces its effective aperture.

For these reasons, it can be just as important to consider the exit pupil that an eyepiece will produce, along with its magnification, since the two are inextricably linked. Too little exit pupil may render the view too dim for the object being viewed. Too much exit pupil and light is being wasted since it's not all fitting through the iris of the observer's eye.

==Calculating Exit Pupil==

===Using aperture and magnification===
One way to compute the exit pupil is to divide telescope aperture in millimeters, by magnification:

<code>telescope aperture in mm / magnification</code>

'''Examples''':

* 200mm / 50x = 4mm exit pupil
* 127mm / 150x = 0.85mm exit pupil

===Using telescope focal ratio and eyepiece focal length===
A slightly more convenient method for computing exit pupil is to divide the eyepiece focal length by the telescope focal ratio

<code>eyepiece focal length in mm / telescope focal ratio</code>

'''Examples''':

* 20mm eyepiece / F4.7 = 4.25mm exit pupil
* 5mm eyepiece / F10 = 0.5mm exit pupil

The interesting thing about this method is that it shows the same eyepiece will produce the same exit pupil in telescopes with the same focal ratio, regardless of aperture. A 1000mm aperture F/4 telescope produces the same view brightness as a 100mm aperture F/4 telescope. This demonstrates that it's ultimately the exit pupil, not the aperture, that governs view brightness.

==Exit Pupil Effects and Considerations==
Exit pupil generally influences the brightness of the view through the eyepiece + telescope combination, but not necessarily in the same way for all objects. Stars are unaffected by exit pupil since they are optical point sources. They cannot be magnified, so their light does not spread out. Thus star brightness is directly governed by telescope aperture.

Meanwhile any object that has a measurable surface area and can be magnified, does get dimmer with exit pupil. This includes the Moon, planets, nebulae, galaxies, and even light pollution and general sky glow.

Since exit pupil affects the brightness of light pollution, but not stars, one way to add contrast to star clusters is to increase magnification. By increasing magnification, the stars will remain the same brightness, but light pollution will get dimmer, thus the contrast of the view will increase.

However, this same trick does not work for galaxies and nebulae. Galaxies and nebulae will get dimmer equally as quickly as light pollution as magnification increases, so contrast does not change.

===Exit Pupil and Astigmatism===

If you have astigmatism in your vision, it typically becomes worse the larger the exit pupil is. Astigmatism in astronomy can be particularly annoying because it causes stars to have a spiky, irregular appearance. The larger the exit pupil, the more this problem will manifest itself.

[http://www.televue.com/images/TV3_Images/Images_in_articles/DioptrixAstigmatismVis.gif This chart from Tele Vue] indicates which levels of astigmatism will manifest at which exit pupils.

If seeing pinpoint-like stars is important to you, then consider choosing an eyepiece that provides enough [[eye relief]] to be used with glasses if that eyepiece will produce a large exit pupil in your telescope.

===Exit Pupil and Nebula Filters===

If you plan on using aggressive line filters like UHC/Narrowband, OIII, or H-Beta filters, then it's usually beneficial to have a large exit pupil. Line filters will dim the view quite a bit because they only permit a narrow spectrum of light to pass through them. If you are already starting off at a small exit pupil that is producing a dim view, adding a line filter could make the view too dim to be usable.

Generally any exit pupil larger than 2mm will work with line filters, but the larger the exit pupil, the better.

===Minimum and Maximum Exit Pupil===

The human eye is ultimately the limiting factor of how large or small an exit pupil can be. Though it depends on individual genetics, human pupils are typically around 7mm in diameter in our 20s, and then get smaller as we age. If an eyepiece and telescope combination produces an exit pupil larger than what our eye can accept, that light is effectively wasted. This can become especially problematic for reflectors and catadioptrics whose central obstruction starts occupying a larger and larger percentage of the light that does enter the pupil. The more oversized the exit pupil is in a telescope with a central obstruction, the more pronounced the secondary shadow will be, and it will often seem like there is a dark, out of focus blob floating in the center of the field of view. Refractors do not have this problem.

While there is some case to be made for breaking the largest usable exit pupil rule in order to achieve a wider true field of view in some cases, the general advice is not to exceed an exit pupil larger than what your own eyes can support. It is worthwhile getting your dilated pupils measured by an optometrist to get a better idea of what your personal maximum useful exit pupil will be.

For minimum exit pupil, it often depends on the target. The brighter the target, the smaller the exit pupil can be before the object becomes too dim. It should be noted that the dimmer the exit pupil, the less light the eye has to work with. This can rob the view of contrast and clarity. Given the rough rule of thumb of not to exceed 50x per inch of aperture, this translates to a minimum useful exit pupil of 0.5mm. However, this is not a hard and fast rule, and it depends entirely on the object. Some small faint objects can effectively disappear from your vision at 1mm exit pupil, while other small bright objects remain easily visible even as low as 0.3mm. Bright objects like planets and the moon can tolerate even smaller exit pupils, but at that point you would be pushing magnification well past the useful limit of the telescope's optics. You'd be sacrificing brightness for no additional detail.

===Exit Pupil vs Magnification===
Exit pupil and magnification are inextricably linked. Increasing magnification will decrease exit pupil, and vice versa. Thus a balance between magnification and exit pupil must be struck. It's generally beneficial to achieve higher magnification at the expense of exit pupil, since our eyes behave linearly with image scale, but non-linearly with brightness. That is, we can tolerate dimmer views better than we can tolerate smaller views. As an example, consider Messier 51 - the Whirlpool Galaxy. When looking at the night sky with the naked eye, you are effectively using a 7mm exit pupil since your eyes are fully dilated. When you look through say, a 6" telescope at 100x, the exit pupil is just 1.5mm - 22x dimmer. But despite the view being 22x dimmer than the naked eye, the fact that it is 100x ''larger'' is what makes M51 visible. Our eyes do not detect small, low contrast things very well, but do detect large low contrast things. Thus using magnification to enlarge low contrast objects is more beneficial than trying to preserve a bright exit pupil.

==Further Reading==

[https://medium.com/@phpdevster/how-telescope-aperture-affects-your-view-24507147d7fc How Telescope Aperture Affects Your View]

[https://www.reddit.com/r/telescopes/comments/7o18zb/what_i_learned_about_observing_in_2017/ A 2017 Reddit post discussing observing and exit pupil]

Getting Started in Astrophotography

2020-01-20T21:15:39Z

Jmh921: /* Altitude-Azimuth Mounts */

'''NOTE: this is a page in progress'''

A lot of people have at least a casual interest in Astrophotography (abbreviated AP). But most people know very little about how AP is done, or what it even is. Many seem to think it's as simple as just plugging a camera into the eyepiece receptacle of a telescope and snapping pictures. In reality, it's far more complex than that.

=What is Astrophotography=

At its heart, AP is about taking pictures of astronomical phenomena. This can be anything from images of the stars at night to images of galaxies and nebulae, and a whole bunch of stuff in-between.

Astrophotography is not a monolithic subject. There are a wide variety of sub-topics in AP, and each have different needs. There's no one-size-fits-all solution. But there is often a lot of overlap.

Let's break down the different kinds of AP:

==Kinds of Astrophotography==

====Star Trail Photography====

This has been a traditional starting point for many astrophotographers and has the least-demanding requirements. Typically all that is needed here is a camera which offers you the ability to capture long exposures and a tripod or some other mount to hold it still.

The bulk of star trail images are taken toward the pole, which shows the rest of the sky turning around the pole itself. Some nightscape images (see below) use star-trail images instead of fixed-star images.

====Nightscape Photography====

Nightscape photography is the type of astrophotography that combines scenery/landscape photography with the night sky overhead.

<gallery mode="packed" widths=200px caption="Examples of Nightscape Photography From APOD">
File: Nightscape1.jpeg|12/07/2018|link=https://apod.nasa.gov/apod/ap181222.html
File: Nightscape2.jpeg|12/18/2018|link=https://apod.nasa.gov/apod/ap181207.html
File: Nightscape3.jpeg|01/24/2019|link=https://apod.nasa.gov/apod/ap190124.html
File: Nightscape4.jpeg|05/16/2019|link=https://apod.nasa.gov/apod/ap190516.html
File: Nightscape5.jpeg|07/24/2019|link=https://apod.nasa.gov/apod/ap190724.html
</gallery>

Nightscape photography is primarily done with DSLR cameras, non-tracking tripods, and standard lenses with short focal lengths.

====Lunar Photography====
As the name suggests, this would be pictures of the moon.

Other than the sun, the moon is the brightest of all astrophotography targets. It's also relatively large. Long exposure imaging is not required for lunar photography, so a tracking mount is not required, though it is generally recommended. The preferred method for lunar photography is done via stacking video frames and processing to produce the most detail.

====Planetary Photography====
Again, as the name suggests, we're talking about pictures of planets here.

For the most part, however, there are only three planets that make good targets for photography: Mars, Jupiter, and Saturn.

•Mercury is too close to the sun, and too small. At its [maximum elongation], it only gets about 19° from the sun, which means that it's never visible far above the horizon. Because of this, any imaging will end up shooting through a thicker air mass, which typically degrades the image significantly. It's also so small that you're not going to see much anyway it its distance. Nevertheless, some people do attempt pictures. In them the most you are likely to see is the phases it displays, similar to those of the moon.

•Venus is not as close to the sun as is Mercury, but, being inside our orbit, it still doesn't rise all that high. At [maximum elongation], it only gets about 45° above the horizon. Venus is also fairly featureless, other than showing phases. The clouds block any surface features, and the patterns in the clouds themselves tend to be fairly subtle. Typically you would need a neutral density filter to reduce the glare, then another filter (I believe violet is the one of choice) to increase contrast enough to make out the features.

•Uranus is too distant and small to show much more than a blue-green disk to most amateur telescopes. Larger amateur scopes can occasionally get more out of it, but rarely.

•Neptune is about the same size as Uranus, but further out still, making any reasonable hope for capturing an image of Neptune somewhat hopeless.

•And if you count Pluto as a planet, just consider that the best image the [[Hubble Space Telescope|HST]] could get is this:

[[File:HST Pluto.jpg|300px|link=https://hubblesite.org/uploads/image_file/image_attachment/20341/web_print.jpg]]

As for extra solar planets: only the largest research telescopes have ever captured direct images of the most massive and nearby such stars. Your amateur scope has no real hope of imaging them, though [[Detecting Extra-Solar Planets|detecting them]] is possible.

====Comet Photography====

Comet astrophotography comes along with some unusual challenges.

There are actually two different kinds of comet astrophotography. The first kind is primarily used for discovering comets. The other is to produce an image of the comet.

Photography for discovering comets - which can also be used for discovering asteroids or even Kuiper Belt Objects (KBOs) and was also the technique used to discover Pluto - involves capturing multiple images of the same patch of sky over time. It can be done during a single imaging session or over several. The images are then compared in an effort to identify any objects that appear to move between the images. The discovery of Pluto utilized a device called a Blink Comparator, which rapidly shifted between images. Today, typically images are merged and a moving object will show up in multiple positions, typically forming a line as it moves through the image.

For capturing detailed images of a comet, the primary challenge comes with the fact that the comet is usually moving at a different rate than the background stars. The closer the comet is to the Earth, the more apparent motion there will be between the comet and the background stars. Sometimes it may take days to notice much of a change, particularly when a comet is far away. Other times, particularly when closest, the movement may seem obvious over minutes or seconds. In a case like this, if trying to capture a long-exposure image, normal tracking at the [[sidereal rate]] will show the stars as you would normally expect to see them, but the comet may appear to be a stretched blur. If you were to track the comet directly, the comet may come out clear, but then the background stars would end up in a blur.

For this reason, special techniques are used for this kind of imaging.

====Solar Photography====

Due to the intensity of the energy involved, solar photography requires some form of filtering to avoid damaging the camera and/or telescope. As with lunar and planetary imaging, exposure times are very short, so mount selection is far less critical. But the filtration option itself can be expensive, depending on the type of solar filtering used.

There are two main types of solar filters: so-called "[[White-Light Solar Filter|White Light]]" filters and [[Hydrogen Alpha Solar Filter|Hα filters]].

White-light filters are fairly inexpensive, but also show the least. A white light solar filter will allow you to see sunspots, transits, and possibly solar granulation (though not clearly).

Hα filters are a whole different ballgame. These combine an energy rejection filter with an etalon which allows for a very narrow bandwidth of light to be viewed. This allows the viewer to see a lot more detail at a specific wavelength of light. This allows the user to see things such as solar prominences (these are frequently, though incorrectly, referred to as solar flares, but flares are a much larger feature). There are other, similar filters for different wavelengths. Calcium K is the second most common such filter, though the vast majority of narrow-band solar filters for amateurs are Hα.

====Deep Sky Photography====

The biggest challenges in AP come with deep sky astrophotography, or DSO AP. There are two key inter-related reasons for this.

The Earth rotates on its axis once every 24 hours. When you factor in the additional movement caused by the Earth's orbit around the sun, the actual apparent rate of motion of astronomical objects in the sky is about 4 minutes short of 24 hours. This is the [[sidereal rate]].

DSO targets include galaxies, nebulae, and star clusters. Each of those can, of course, be sub-divided.

The easiest overall division here to use is by [[Angular Measure]]. Targets which require a wider field of view (for example [[NGC]] 7000, the North America Nebula M31, the Andromeda Galaxy, and the Veil Nebula), typically require telescopes with shorter focal lengths, cameras with larger image sensors, and are less demanding on the tracking accuracy of the mount.

On the other hand, objects with smaller angular measurements, such as most planetary nebulae and many galaxies, typically need more magnification. This requires longer focal lengths and/or smaller image sensors. This, in turn, decreases the width of the field of view, which puts greater demands on the mount's tracking accuracy. Even with autoguiding, many mounts are simply not well suited to this task.

=Equipment=

For any kind of astrophotography, there are three main pieces of equipment needed:

* the Camera
* the Telescope or other optics
* the Mount

Different types of AP have different requirements, and those requirements will depend on the specific needs of the type of AP being done.

==Telescope Mounts==

For most types of astrophotography, the mount is, without question, the most important piece of equipment. For Lunar and Planetary astrophotography, it's not as critical, and for Star Trail and Nightscape photography, it's not very important at all (you still need SOMETHING to hold the camera, however). But for deep sky astrophotography of any sort, it is absolutely critical.

When it comes to deep sky astrophotography, you could have a million-dollar top-of-the-line camera and a million-dollar top-of-the-line telescope, but without a mount that can handle the load and provide accurate motion, you will not get good images. Conversely, a mediocre telescope and camera on a quality mount can often produce pretty good images. For this reason, it is always recommended that you focus on the mount first, then payload second.

The reason this is so critical is due to the apparent motion of the sky caused by the rotation of the Earth on its axis and the requirement of long exposures to capture an image of the object being photographed. If, during the duration of the exposure, the object moves with relation to the camera and telescope, the image will show blurring and stretching or streaking. The job of the mount is to counteract this motion.

The term mount refers to the overall piece of equipment that holds up the telescope and/or camera and is used to point/aim them at a particular object. People not familiar with the workings of telescopes often refer to mounts as tripods. Many telescope mounts do use tripods, but not all. The tripod is not the key portion of the mount. What a tripod is is a type of support structure for the portion of the mount that does the work of pointing the telescope, which is referred to as the mount head. A mount head and tripod or other support structure (such as a pier), together make up the mount, though the mount head itself is often simply referred to as the mount.

(note: insert image here of the iOptron iEQ45 Pro mount head alone, with tripod, and with pier. Also insert a picture of a camera tripod and a Dobsonian base.)

In order to move (or slew) the telescope to point at an object, the mount must be able to move in two or more axes of motion (not, here the term axes does not refer to what you use to chop firewood, but as the plural of axis). There are two common types of motion used for telescope mounts, and mounts can be broken down into two groups based on those types of motion.

===Altitude-Azimuth Mounts===

The simplest type of mount motion is what is known as altitude-azimuth, or alt-az. Altitude refers to the angle above or below the horizon, while azimuth refers to the angle along the horizon, left or right. Azimuth measures usually are given between 0° and 90° Typically, the [[zenith]] is considered 90° altitude and the horizon is 0°. For Azimuth, 0° or 360° is typically due North, 90° is due East, 180° is due South, and 270° is due West. Alt-az coordinates are relative to the observer's position, and for astronomical objects, they are relative to the observer's position on the Earth as well as the time and date of the observation. If a person in New York sees Jupiter at an altitude of 60 degrees above the horizon, to an observer in Chicago, it would only be 45 degrees above the horizon at that time, but will reach 60 degrees about an hour later.

Alt-az is intuitive for most people. We liver our lives in a left-right, up-down manner. But for astronomy, this often presents problems. This is because we live on the surface of a rotating planet that is roughly spherical. While objects in the universe do move, the rate of motion is typically very low, which means they don't appear to be moving at all from our vantage point over the course of minutes, hours, days, or even years. If the Earth was not rotating or orbiting the sun and you were to look up at the night sky, other than things in our solar system, the positions of everything out there would not seem to change at all except over long periods of time. But because the Earth is rotating at a rate of 1 rotation per day, from our vantage point it appears those objects are moving.

Imagine you are on a merry-go-round and looking out from the center. Everything around you would seem to be moving, circling around you. But, in fact, you're the one moving, not the world around you. This is essentially what's happening with the Earth and the universe around us.

If you follow objects across the sky at night, you'll notice that they don't move in straight lines, but follow paths that arc across the sky - a portion of the full-circle created by the Earth's rotation. If you are in the Northern Hemisphere and a star is rising on the Eastern Horizon, as the star rises you will notice it appear to be moving a bit south as well, until it reaches the [[meridian]]. At that point it will start setting, moving toward the western horizon and appear to be moving slightly north to set at a point 180 degrees from where it rose. In the Southern Hemisphere, the same thing happens only the stars appear to move a bit north as they rise and south as they set. If the star were to draw a line across the sky as it went, this line would be an arc, not a straight line.

And here is where an alt-az mount starts to have difficulties, particularly for photography. In order to move in such a way as to follow as star, or planet, or nebula, or any other astronomical body, the mount must move in both the altitude and azimuth axes at rates that are not only different from one another, but also vary depending on the object's location in the sky. Not only that, but they may change direction in the altitude axis - as they rise the altitude increases, as they set it decreases.

In order for an alt-az mount to "track" - follow - an object across the sky, it must be computerized. In mounts with this functionality, a computer maintains an internal mathematical model of the Earth and the sky. When you start up such a mount, the computer must be initialized (given starting values) for the time and date and its location on the surface of the earth (Latitude, Longitude, and Altitude). Once it knows where it is and what time and day it is, it can determine where everything in the sky should be relative to its position. It then must synchronize the calculated positions with its own orientation. This is typically done by identifying a handful of stars from a list of bright stars, pointing the telescope at one of the stars, and telling it what it's looking at. With two or three such stars, the mount should be relatively accurate and capable of [[slewing]] to a requested set of coordinates. To follow an object, once an object to follow is designated, it must then calculate what it's looking at and how it needs to move to follow the object. This calculation must be done every time it needs to move to follow the object - usually several times per second.

But there's a bit of a problem here: each calculation relies on the results of the previous calculation, which ultimately rely on the initial values entered during setup and alignment. If those values aren't accurate, neither will be the resulting calculation results. And the calculation errors can compound over time.

For the most part, alt-az telescopes simply lack the accuracy to do this well enough for photographic use. There are some exceptions. Imaging that does not require long exposures, such as planetary imaging, may be possible, and there are some very high-end systems that are accurate. These often are significantly more expensive and use computerized-pointing systems based on plate-solving and modeling the unique characteristics of the particular telescope and mount - something known as a [[Tpoint Model]].

Another problem with alt-az mounts is a problem known as [[frame rotation]]. Frame rotation is the apparent rotation of an object in the field of view as it moves across the sky. To better understand this, consider the following: If you look at the Constellation Orion, the westernmost star on its belt (which rises before the other two belt stars) is named Mintaka. This star is nearly on the celestial equator. The bright star Betelgeuse, which is easily identified by its red-orange color, sits in Orion's eastern "shoulder" which is about seven and one-half degrees north of the equator, which puts it to the left of Mintaka as Orion is rising. The blue-white supergiant Rigel which forms the south-west most "toe" in the constellation is roughly 8 degrees south of the equator, putting it to the right of Mintaka when rising. If you follow the constellation across the sky until it sets, as it is setting you will notice that Betelgeuse is now to the right and Rigel to the left. Betelgeuse is still to the North, and Rigel to the South, but you have rotated 180 degrees to see them set. If you were to follow them the entire night through an alt-az telescope, you'd watch the stars appear to rotate in the field of view. In fact, you are the one rotating as you follow them.

For long exposure imaging, this is a major problem. There are devices available to rotate along with the object as you move across the night sky, but these tend to be somewhat expensive and are not in widespread use.

Overall, this makes alt-az mounts less suited for imaging, and not recommended for those interested in imaging. They are, however, easy to use and often less expensive than the alternative, making them a favorite among visual observers.

Level 2

===LEVEL 3===
Level 3
====LEVEL 4====
Level 4
=====LEVEL 5=====
Level 5

Recommended Software and Apps For Astronomy

2019-10-30T17:27:13Z

Jmh921: /* Microsoft Windows */

This page is intended to provide a list of helpful astronomy tools and applications. Please feel free to add or edit information here.

If you would like to add content please include a link to the website for the product, if possible, as well as a short description.

Unless otherwise specified, it is assumed that all apps and products listed here are available and run under the current version of whichever operating system they are listed under.

If a program/app is available for more than one operating environment, please be sure to list it under all applicable environments.

It may also be desirable to create a separate page for some individual apps/programs/software suites. Feel free to do so if you like.

=Web Apps=

These tools are web-page based and should work on most browsers on any device.

*[http://astronomy.tools/ Astronomy Tools] Field of view calculators, telescope calculators, CCD/Imaging calculators, weather forecasts, star charts, and more. Run by [https://www.firstlightoptics.com/ First Light Optics] in England.
*[https://app.photoephemeris.com/?ll=29.665685,-96.719821&dt=20191030111300-0500&z=14&spn=0.04,0.09&center=29.6578,-96.7128 The Photographer's Ephemeris]

=Microsoft Windows=

==Planetarium, Charting, Telescope Control==
*[http://www.ccd.bisque.com/sc/pages/TheSkyX-Editions.aspx The Sky by Software Bisque]
*[https://www.ap-i.net/skychart/en/start Cartes du Ciel] - free/open source
*[https://www.hyperion-astronomy.com/pages/prism-landing Prism]
*[https://stellarium.org/ Stellarium] - free/open source

==Astrophotography==

===Image Capture===

*[http://www.stark-labs.com/nebulosity.html Nebulosity]
*[https://www.otelescope.com/ Backyard EOS/Backyard Nikon]
*[http://diffractionlimited.com/product/maxim-dl/ MaximDL]
*[http://mainsequencesoftware.com/products/sgpro SGP (Sequence Generator Pro)] - limited functionality available in Sequence Generator Lite, full features unlocked with licensed Pro version.
*[https://nighttime-imaging.eu/ Nighttime Imaging 'N' Astronomy (NINA)] - free/open source
*[https://ideiki.com/astro/Default.aspx APT (Astrophotography Tool)] - unlicensed "trial" version provides majority of functions, licensed version unlocks additional features.
*[https://openphdguiding.org/ PHD (Push Here Dummy) Auto Guiding]

===Image Calibration, Stacking, and Processing===

*[https://pixinsight.com/ PixInsight]
*[http://deepskystacker.free.fr/english/index.html DeepSkyStacker] free/open source
*[https://www.astronomie.be/registax/ Registax] - free/open source
*[https://www.autostakkert.com/ AutoStakkert] - free/open source
*[https://www.adobe.com/?mv=search&sdid=KKQXH Adobe Photoshop and Creative Cloud] - Essentially the gold-standard for all-purpose photo editing, Photoshop and the other Adobe Creative Cloud products have gone to a subscription-based service. At present, Photoshop is available (bundled with LightRoom) for $9.99/mo and includes 20GB of cloud storage.
*[https://www.gimp.org/ GIMP] - the GNU Image Manipulation Program (GIMP) is an free/open-source alternative to Photoshop, available for Windows, Macintosh, and Linux operating systems.

===Utility===

*[https://ascom-standards.org/index.htm/ ASCOM] - The ASCOM Initiative is a loosely-knit group of developers and astronomical instrument makers that work together to bring vendor-independent and language-independent plug-and play compatibility between astronomy software and astronomical instruments on Windows (and soon Linux and MacOS) computers. ASCOM stands for the Astronomy Common Object Model. It can be used to control Telescopes, Mounts, Focusers, Cameras, Filter Wheels, and Observatories (domes/roofs).

*[https://ascom-standards.org/Developer/Alpaca.htm ASCOM Alpaca] - the original version of ASCOM is windows-only based on microsoft's COM technology. ASCOM Alpaca is being developed to extend functionality to other operating environments such as Mac OS and Linux. Alpaca is independent of Windows and does not dependent on COM.

*[https://indilib.org/ INDI - Open Astronomy Instrumentation] - INDI is an alternative to ASCOM, released under the GNU LGPL (open-source licensing) and not specific to any operating system.

=Apple Macintosh=

=Linux/Unix=

=iOS Phone and Tablet Apps=

=Android Phone and Tablet Apps=

=Other Apps/Softare=

Recommended Software and Apps For Astronomy

2019-10-30T17:01:42Z

Jmh921: /* Planetarium, Charting, Telescope Control */

Recommended Software and Apps For Astronomy

2019-10-30T16:58:44Z

Jmh921:

Recommended Software and Apps For Astronomy

2019-10-30T16:53:23Z

Jmh921: Created page with "This page is intended to provide a list of helpful astronomy tools and applications. Please feel free to add or edit information here. =Web Apps= These tools are web-page..."

This page is intended to provide a list of helpful astronomy tools and applications. Please feel free to add or edit information here.

=Web Apps=

These tools are web-page based and should work on most browsers on any device.

*[http://astronomy.tools/ Astronomy Tools] Field of view calculators, telescope calculators, CCD/Imaging calculators, weather forecasts, star charts, and more. Run by [https://www.firstlightoptics.com/ First Light Optics] in England.
*[https://app.photoephemeris.com/?ll=29.665685,-96.719821&dt=20191030111300-0500&z=14&spn=0.04,0.09&center=29.6578,-96.7128 The Photographer's Ephemeris]

=Microsoft Windows=

==Planetarium, Charting, Telescope Control==
*[http://www.ccd.bisque.com/sc/pages/TheSkyX-Editions.aspx The Sky by Software Bisque]
*Cartes du Ciel
*Prism
*Stellarium

==Astrophotography==

===Image Capture===
*CCD Soft
*Nebulosity
*Backyard EOS/Backyard Nikon
*MaximDL
*Sequence Generator Pro (SGP)
*NINA

===Image Processing===

*PixInsight
*DeepSkyStacker
*Registax
*Astrostakkert

=Apple Macintosh=

=Linux/Unix=

=iOS Phone and Tablet Apps=

=Android Phone and Tablet Apps=

=Other Apps/Softare=

Astronomy Clubs

2019-10-08T18:45:12Z

Jmh921: /* Club Dues */

Astronomy Clubs

2019-10-08T18:41:02Z

Jmh921:

Astronomical Society

2019-10-08T18:32:19Z

Jmh921: Redirected page to Astronomy Clubs

#REDIRECT [[Astronomy Clubs]]

Astronomy Clubs

2019-10-08T18:30:52Z

Jmh921:

Astronomy Clubs

2019-10-02T22:09:12Z

Jmh921:

Here you can find a list of astronomy clubs around the world. Please feel free to add your own if it is not listed.

'''United States'''

*[https://www.astroleague.org/astronomy-clubs-usa-state Astronomical League] The Astronomical League is a collection of clubs throughout the United States. The link provided will allow you to find a club near you within your state.

*[https://nightsky.jpl.nasa.gov/club-map.cfm Night Sky Network] The Night Sky Network, or NSN, is a partnership between NASA/JPL, The Astronomical Society of the Pacific, numerous individual astronomy clubs and societies, the Institute for Learning Innovation, and several other organizations with an interest in science, astronomy, and education. They include a listing of clubs and events, searchable by Zip Code.

*[https://www.go-astronomy.com/astro-club-search.htm Go Astronomy Club Lists] Go Astronomy is a website with a variety of resources for astronomy, and worth a look for many reasons. They also include a very extensive directory of clubs, societies, observatories, and planetariums, mostly n the United States.

*[https://www.skyandtelescope.com/astronomy-clubs-organizations/ Sky And Telescope] Sky And Telescope magazine's online site also has a database of clubs, organizations, museums, observatories, and more. Their content is focused on the United States, but includes international content as well. Their database does not appear to be particularly well curated, however, and club listings may be out of date.

'''United Kingdom'''

*[http://www.astronomyclubs.co.uk/Clubs/Counties.aspx UK Clubs] This link provides a list of clubs by county in the UK.

'''Europe'''

*[https://eas.unige.ch/affiliates.jsp European Clubs] This link provides a list of clubs in Europe.

'''Austrailia'''

*[https://astronomy.org.au/amateur/amateur-societies/australia/ Austrailian Clubs] This link provides a list of clubs in Austrailia.

'''Canada'''

*[https://www.skynews.ca/resources/astronomy-clubs/ Canadian Clubs] This link provides a list of clubs in Canada.

MediaWiki:Deletereason-dropdown

2019-10-02T21:57:53Z

Jmh921: Created page with "* Common delete reasons ** Spam ** Vandalism ** Copyright violation ** Author request ** Broken redirect ** Duplicate Content"

* Common delete reasons
** Spam
** Vandalism
** Copyright violation
** Author request
** Broken redirect
** Duplicate Content

Invention of the Telescope

2019-10-02T20:59:06Z

Jmh921: Created page with "It is a popular misconception that Galileo Galilei invented the telescope. While Galileo is largely responsible for turning the telescope into an astronomical instrument, the..."

It is a popular misconception that Galileo Galilei invented the telescope. While Galileo is largely responsible for turning the telescope into an astronomical instrument, the telescope was not his original invention.

The actual invention of the telescope is shrouded in the murky fog of history, with some claims going back hundreds of years before Galileo.

==Early 1600's Netherlands==

The credit for the modern invention of the telescope is typically given to a Dutch optician named Hans Lippershea. In 1608, Lippershea applied for a patent on his device. His application preceded that of another dutchman, Jacob Metius, by a few weeks. Both patents were, however, rejected. The patents were rejected as the concept appeared to already be well-established and, therefore, the invention was not deemed worthy of patent.

In 1655, William de Boreel investigated the history of the telescope and, based on the claim if Johannes Zachariassen that his father, Zacharias Janssen, invented the instrument as early as 1590, determined this was the true inventor. However this is entirely based on Zachariassen's claim, and he is therefore typically not credited with the invention.

What appears fairly certain, however, is that the inventions of Lippershea, and, possibly, to a lesser extent Metius, were what lead to the popularization of and advances in the design of the modern telescope. While both patents were refused, both received commissions from the Hague to manufacture more examples of their design, which began to proliferate through the region.

In 1609, Jaqcques Bovedere, a French scientist, appears to have been introduced to the device in Paris. Bouvedere was an associate of Galileo's and apparently described the instrument to the Italian scientist, who then, based on the descriptions, set out to construct his own.

It is fair, then, to say that Galileo designed and built his own instruments, and most likely some of his improvements became part of the designs that proliferated around Europe.

==Earlier Claims==

Getting Started in Astrophotography

2019-09-26T19:20:52Z

Jmh921: /* LEVEL 1 */

Getting Started in Astrophotography

2019-09-16T23:28:17Z

Jmh921: /* Kinds of Astrophotography */

Getting Started in Astrophotography

2019-09-16T23:23:31Z

Jmh921: /* Deep Sky Photography */

Getting Started in Astrophotography

2019-09-06T14:12:53Z

Jmh921: /* Deep Sky Photography */

Getting Started in Astrophotography

2019-09-04T15:53:01Z

Jmh921: /* Solar Photography */

Getting Started in Astrophotography

2019-09-03T21:38:43Z

Jmh921: /* Comet Photography */

Getting Started in Astrophotography

2019-08-28T23:30:31Z

Jmh921: /* Comet Photography */

Getting Started in Astrophotography

2019-08-28T21:45:36Z

Jmh921: /* Lunar Photography */

Getting Started in Astrophotography

2019-08-28T21:22:01Z

Jmh921: /* Nightscape Photography */

Getting Started in Astrophotography

2019-08-07T23:18:42Z

Jmh921: /* Planetary Photography */