Magnification, Field Of View, Exit Pupil and
Limiting Magnitude Calculator
Click here for a
Secondary Mirror Offset Calculator
Exit Pupil Diameter³:
Field Of View:
In the first four boxes, please enter the diameter and focal length of your telescope, and the focal length and apparent field of the eyepiece you wish to use. If you are not sure of the Apparent Field of your eyepiece, click the "Apparent Field" Link for a list of some of the more common eyepiece types. Click "Calculate" to show a summary in the second box, and a full analysis in this box. This Analyser, including all calculations and formulae contained within, is Copyrighted in full to Lachlan MacDonald (© 2010 Lachlan MacDonald). No part of this document may be used elsewhere than at this location, without prior express written authorisation from the author.