[Andy01 (Andy)]

Originally Posted by Dennis

Hi Andy

Have a look at this site.

http://www.howardedin.com/articles/fov.html

Select your camera (40D) and enter your lens focal length and it provides the FOV.

For your telescope, the focal length will be 770 x 0.85 = 655.

Another very useful resource is:
http://www.wilmslowastro.com/software/formulae.htm

Cheers

Dennis

Awesome, that's most helpful!
Thanks heaps Dennis

Cheers
Andy