F = focal length of main (objective) lens/mirror
D = aperture thereof
f = focal length of eyepiece
magnification M = F/f
focal ratio = F/D (this is the quantity photographers quote as f/10 etc))
exit pupil = f / (F/D) = fD / f
actual field of view = (apparent field of view) / M
(eg if eyepiece has an apparent field of 55 deg, and its focal length gives it a magnification of 40x with your telescope, actual field of view - ie the size of the bit of sky you can see - is 55/40 = 1.38 deg, or well over 2 Moon-widths)
Anti-nuisance lawsuit warning: The purpose of these notes is to remind me, Zoegond, of stuff or to help me work stuff out. They may contain mistakes.
Quick
- ($a, $b....) = unpack("A2A7...", $packed)
- push( array, list )
