View Single Post
  #8  
Old 24-05-2019, 08:22 PM
phomer (Paul)
Registered User

phomer is offline
 
Join Date: Nov 2009
Location: Maribyrnong
Posts: 158
Quote:
Originally Posted by Stefan Buda View Post
I need to make a camera adapter to mount a QSI683 on a CDK250 but the information I have does not make sense to me.
Can someone please explain to me how a filter or a window makes the required adapter shorter? Please read the small print about the back focus being reduced by the thickness of the glass/3.

Stefan,


I recall getting totally lost on this when I needed an adaptor. A glass filter will extend the focus point 1/3 of the filter width further away from the objective or mirror. It effectively extends the focal length, so you would need to increase the adapter length.


Paul
Reply With Quote