View Single Post
  #2  
Old 01-03-2018, 10:23 AM
billdan's Avatar
billdan (Bill)
Registered User

billdan is offline
 
Join Date: Mar 2012
Location: Narangba, SE QLD
Posts: 1,551
Peter, you can work out where the dust bunnies are by this formula

Distance from CCD chip (mm) = (P x FR x d ) / 1000

where P = pixel size in microns, FR is focal ratio and d is the diameter of the dust bunny in pixels.

This formula also works for halo reflections as well.

Cheers
Bill
Reply With Quote