Magnification, Field, and Exit Pupil Calculator

Primary Diameter (inches):
Primary Diameter (millimeters):

Primary Diameter (mm):
Focal Length (mm):
f Ratio:
Eyepiece Focal Length (mm):
Magnification:
Eyepiece Exit Pupil (mm):
Eyepiece Apparent Field (degrees): (typ Plossl=55, Nagler=82)
Eyepiece True Field (degrees):
Eyepiece True Field (arcminutes):
Field transit time @ Latitude (minutes):

The Math: diameter_mm = diameter_inch * 25.4 , f number = fl / diameter , fl = diameter * f number , mag = fl / eyepiece fl
pupil = diameter / mag , eyepiece_true_field = eyepiece_apparent_fov / mag
eyepiece_true_field_arcminutes= eyepiece_true_field * 60 , transit_time = eyepiece_true_field * 4