[APML]: Re: "Doughnuts" in AP Scope - THE ANSWER

[mwcook@concentric.net]

    After discussing the AP "doughnut" image problem with Roland
and doing an "open" camera test, I believe we have resolved the 
source of the image distortion.  So for the archives, here's the 
answer:

    The shots were made with the AP 2x Barlow and both pieces of the 
AP camera adapter.  I was using the front section of the camera 
adapter intended for eyepiece projection as a focus extension.  It is 
now obvious what was happening.  Without an eyepiece, the two smooth 
areas on either side of the eyepiece clamp ring was reflecting the 
image.  I could see it clearly doing Roland's recommended "open 
camera" test.  Using only the short piece of the camera adapter and 
adding the proper AP focus extension tube before the Barlow 
eliminated the problem.

    Roland said that when you see an image effect like rings or 
patterns in the photos, look for the problem close to the camera
opening.  This certainly proved true in my case.  

    Thanks to APML for the help and especially the email address 
for Roland.




    

de Mike, AF9Y
http://www.webcom.com/af9y
Work: mwcook@itt.com
Home: mwcook@cris.com
      af9y@iquest.net