Re: [ATM] Vignetting at focuser/Crayford protrusion

[Michael Lindner <mikell@optonline.net>]

On Wednesday 02 June 2004 09:37 pm, Gary Seronik wrote:
> Don't worry about the 75% ray -- if you were
> vignetting the 100% ray you'd have a problem, but not with the 75% ray.

Actually, vignetting the 100% ray would be fine too, as long as the vignetting 
is at the focuser. What this means is that the size of the 75% or more 
illuminated area is larger than the focuser drawtube (in other words, even 
the edge of the field in the focuser is at least 75% illuminated). Read The 
Fine Manual. :-)

Clear skies.
-- 
Michael Lindner
http://www.starastronomy.org *** http://home.att.net/~mikel
http://www.atmsite.org *** http://www.atmlist.net

_______________________________________________
ATM mailing list http://www.atmlist.net/