Re: [ATM] Ghost image

[Chuck Broward <cbroward@ufl.edu>]

Hi, We built a truss dob using a Coulter 17.5 inch mirror, and it often 
produces a similar problem...seems to be related to
a mirror cell that makes the mirror take a slight (doesn't take much) 
potato chip kind of shape.  We can get rid of it by very careful
assembly care--to keep from twisting the mirror cell.  We tracked this 
down when we hung barbell weights on the mirror cell frame
to balance the scope.  We now use a virtual counterweight 
instead...image quality much better.

Chuck,  Alachua Astronomy Club

vorblesnak@peak.org wrote:
> Mel Bartels wrote ..
>
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>> Oh sounds like reflections caused by each of your eyepieces.  How many
>> eyepieces have you tried?
>>     
>
> I used the original that came with the scope a no name wide field of some
> sort.  My Meade Super Plossel 25mm and a Lanthanium 15mm.  All showed the
> ghost.  You suggested pinched optics, primary or secondary mirror?
>
> David Davis
> Toledo, OR 97391
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