Answer. - an Astronomy Net ATM Forum Message

ATM Forum Message
Forums:	Atm · Astrophotography · Blackholes · Blackholes2 · CCD · Celestron · Domes · Education Eyepieces · Meade · Misc. · God and Science · SETI · Software · UFO · XEphem


Home \| Discussion Forums \| Amateur Telescope Making \| Post	Login

Be the first pioneers to continue the Astronomy Discussions at our new Astronomy meeting place...
The Space and Astronomy Agora

Answer.

Forum List | Follow Ups | Post Message | Back to Thread Topics | In Response To
Posted by Robert May on December 20, 2001 21:45:58 UTC

Go look up the Stevick-Paul design.
The offaxis parabola produces coma if care isn't taken to remove it from the end product. It's the nature of the beastie. Long focal length newtonian designs help by making the coma very minimal even when a offaxis spherical mirror is used.
Short FL designs make a lot more problems than long FL ones do. Unfortunately, long FL designs also don't have the FOV of a short FL design so it's all a tradeoff.

Follow Ups:

Thanks Bob, I knew they had to be a reason. - mpinson - December 21, 2001 - 01:01 UTC

Additional Information

About Astronomy Net | Advertise on Astronomy Net | Contact & Comments | Privacy Policy

Unless otherwise specified, web site content Copyright 1994-2023 John Huggins All Rights Reserved
Forum posts are Copyright their authors as specified in the heading above the post.
"dbHTML," "AstroGuide," "ASTRONOMY.NET" & "VA.NET"
are trademarks of John Huggins