Quote:
Originally Posted by tailwag
I recall there is a formula around somewhere to work out your power, it's something like the focal length divided by the mm size, or something similar
|
Magnification = scope focal length / eyepiece focal length
True field of view = apparent fov / magnification
exit pupil = scope aperture / magnification , or eyepiece focal length/ scope focal ratio
So for a 20mm plossl we get:
Mag= 1200/20 = 60x
Tfov = 50degrees/ 60 = 0.83 degrees
exit pupil = 150mm/60 = 2.5mm