Re: [APML] E210 Coma

[Herm <hermperez@worldnet.att.net>]

I would say really look at collimation before anything else.. and at that f
ratio collimation must be difficult to achieve.

"Gene Horr" <genehorr@houston.rr.com>  wrote:

>>  My understanding is focus doesn't cause coma anyway.
>
>Well, actually I've seen distortion when collimation
>is not perfect when you are out of focus.  And the effects 
>start at the edge and work inwards the more you are out of
>focus.  It may be field curvature rather than coma but
>the results are oblong stars.

Herm
Astropics http://home.att.net/~hermperez

_______________________________________________
Astro-Photo mailing list
Astro-Photo@seds.org
http://seds.org/mailman/listinfo/astro-photo