View Single Post
  #4  
Old 15-04-2014, 08:27 PM
rally
Registered User

rally is offline
 
Join Date: Sep 2007
Location: Australia
Posts: 896
Have you allowed for any adapters - if necessary ?

I'm not familiar with the FF - but if the backfocus or metal back distance specified for that FF is what you say, then so long as the distance from the back of the FF to the CCD is correct it should work.
You usually have a little bit of latitude on most FFs where an error really doesnt make much difference - that may up to a 1-2mm range
So if you are worried about being precise to the micron, you dont need to be, especially give the range of adjustment you mentioned.
Most FFs dont have any adjustment

Where it gets trickier is when you have filters or other optical elements in the optical train - where the optical distance and the physical distance may be different to each other
The AO8 actually does this too but if you have specified the SBIG specified distance that will be fine
Reply With Quote