View Single Post
  #14  
Old 27-07-2007, 10:37 PM
[1ponders]'s Avatar
[1ponders] (Paul)
Retired, damn no pension

[1ponders] is offline
 
Join Date: Nov 2004
Location: Obi Obi, Qld
Posts: 18,778
Here is a comparison of the 300D with the same FOV as the ToUcam. This is using a 6x barlow. If the ED80 has an f ratio of f/7.5 then the ratio will jump to f/45. This means if it will take 2 to the power of 37.5 (a huge number) times longer to achieve the same level of exposure as the straight ED80.
Attached Thumbnails
Click for full-size image (ED80 and 300D and 6X barlow.JPG)
31.3 KB7 views
Reply With Quote