Re[2]: ATM 6" f/4 or not?

[Tom.Stock@gsbsc.gensig.com]

     This is what I got from Newt when I ran the 6" f/4 with a 1.52" 
     secondary and 1-1/4" focuser...
         
     
     
         Angular field of view for the 100% illum-
         inated area is -1.48 degrees.  The diam-
         eter of the field is -0.6166 inch.
     
         Angular field of view for the 75% illum-
         inated area is 1.547 degrees.  The diam-
         eter of the field is 0.6446 inch.

        -tom


______________________________ Reply Separator _________________________________
Subject: Re: ATM 6" f/4 or not?
Author:  Neil Pegg <Neil.Pegg@src.bae.co.uk> at Internet2
Date:    9/17/96 5:12 PM



Hi tom,

You asked ...


>        I recently purchased a partially completed 6" mirror from a 
>     friend.. apparently this being his first mirror, he thought he was 
>     making an f/8 but actually made it f/4...it is almost completely 
>     polished, but f/4 seems a little impractical for a 6" scope... 
>     
>     Does anyone have any advice as to what I should do with this 
>     mirror?
     
This mirror should make a good RFT.
I've just finished a 6" f/3.9 newt with a 1.5" secondary. 
I'm using a 25 mm Lanthanum (LV) eyepiece with it.
Initial views of the moon and brighter stars look good ... should 
be even better when I get the mirror aluminised 8^)
     
What do other people think about a system like this?
If you get the full correction on this mirror and a smooth figure 
then any scratches should have little influence on the image. 
After all, a four-vane spider = 4 big scratches anyway.
     
Good viewing
     
Neil
     
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From:    Neil E Pegg
email:   Neil.Pegg@src.bae.co.uk
     
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