· Get a Cloudy Nights T-Shirt · Submit a Review / Article    Click here if you are having trouble logging into the forums Cloudy Nights - Official Forums of the 2009 International Year of Astronomy Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu.... uh, User   You are not logged in. [Login] Forum Archives · Entrance · Main Index · Search · New user · Who's Online FAQ · Calendar Equipment Discussions >> ATM, Optics and DIY Forum Previous   Index   Next   Threaded   Pages: 1 Waldemar member Reged: 08/02/08 Posts: 10 Loc: Netherlands Extended C-11 ??       #3358030 - 09/26/09 02:52 PM Edit   Reply   Quote Quick Reply   Hi all, I heard a story about an extended C-11, meaning the distance between primary and secundary mirror was extended with about 20 cm (8 inches), which gave a lot less coma. Anyone heard about this? It sounded a bit strange to me, because I thought the distance between primary and secundary is kind of determined by the the shape of both mirrors... I am realy curious if one of you knows something about this. Thanks for any answer. -------------------- Two things are infinite: the universe and human stupidity; but I'm not sure about the universe. A. Einstein Post Extras:       Pages: 1 Previous   Index   Next   Threaded   Extra information 1 registered and 6 anonymous users are browsing this forum. Moderator:  Don W, Mike I. Jones  Print Thread Forum Permissions       You cannot start new topics       You cannot reply to topics       HTML is disabled       UBBCode is enabled Thread views: 79 Jump to *International Year of Astronomy 2009* -----   Global Coordination   Cornerstone Projects   Special Projects   Special Task Groups   Global Activities   National and Regional Activities   IYA 2009 in Africa   IYA 2009 in the USA*Announcements and News* -----   Cloudy Nights Announcements   Discussion of CN Articles, Reviews, and Reports   Beginners Forum   Celestial Events   Light Pollution*Equipment Discussions* -----   ATM, Optics and DIY Forum   Binoculars   Binoviewers   Cats & Casses   Classic Telescopes   Equipment   Eyepieces   Mounts   Observatories   Reflectors   Refractors    Celestron SkyScout and Meade mySky   Video and Electronically Assisted Astronomy*Astrophotography and Sketching* -----   Beginning and Intermediate Imaging   Film Astrophotography   DSLR & Digital Camera Astro Imaging & Processing   CCD Imaging & Processing   Solar System Imaging & Processing   Sketching   Astro Imaging/Sketching Contest *Observing* -----   NEO   General Observing   Planetary and Solar System Observing   Lunar Observing   Deep Sky Observing   Double Star Observing   Solar   Variable Star Observing and Radio Astronomy*Telescope Specific Forums* -----   Celestron NexStar    NexStar GPS / CPC Telescopes   Questar Forum   Meade ACF/RCX / LX / GPS    Meade ETX*Other* -----   Science of Astronomy & Space Exploration   AstroWebsites   Space Rocks*Speciality Forums* -----   AstroArt   Astronomy Software & Computers   Stellar Media   Astro Outreach, Clubs and Star Parties*CN Feedback and Vendor Announcements* -----   Vendor and Group Announcements CN Forums Home

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