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Re: ATM Testing Help???

 Ron
It seems that you are trying to test the very edge of the mirror at 8" radius instead of about 95% of the mirror's radius. Here are a couple of links for couder masks, and one more for crunching your numbers.
Don't forget to use the clear face diameter,(mirror diameter less chamfer), and to test at the effective radius (centre) of each zone.
Clear Skies
Sam Orawski
Canada
 
 
http://www.atmsite.org/contrib/Carlin/couder/#Zone%20Number%20Calculator

http://www.stellafane.com/atm/atm_mask/atm_zone_calc.htm

 http://members.aol.com/aplanatic/figure45.htm

 

----- Original Message -----
From: Ron DePack
To: ATM
Sent: Friday, August 31, 2001 12:22 PM
Subject: ATM Testing Help???

Hi,
 
I need some help crunching the numbers for my mirror.  I had trouble collimating and star testing, I ended up buying a cheshire sight piece but could not try it because of the weather :-(  Below are the reading I have currently, all reading are the average of 3 readings each 90 degrees apart, and I included information for you metric guys.  Please let me know what the next step should be,  Is it done or should I continue to figure???
 
 
f/4.515
Mirror                  16"
Focalt Lenght       72.24"
ROC                   144.480"
Mirror thickness   1"
Secondary           2.9"
 
            Zone        Reading
Zone    1    3.3"        .045"
           2    4.6"        .1195"
           3    5.7"        .2025"
           4    6.5"        .2825"
           5    7.3"        .346"
           6    8.0"        .428"
 
 
 
_______________________________
All readings converted to Metric
 
 
f/4.515
Mirror                    406.4mm
Focalt Lenght        1834.89mm
ROC                     3669.799mm
Mirror thickness     25.4mm
Secondary             73.660mm
 
 
                 Zone          Reading
Zone    1    83.82          1.143 
           2    116.84        3.0353
           3    144.78        5.1435
           4    165.1          7.1755
           5    185.42        8.7884
           6    203.2         10.8712
 
Thanks in advance,
Ron DePack