Introduction

How is magnification calculated for telescopes?

How is magnification calculated for telescopes?

The magnification of an astronomical telescope changes with the eyepiece used. It is calculated by dividing the focal length of the telescope by the focal length of the eyepiece (focal length of telescope / focal length of eyepiece = overall magnification). For example, a telescope with a 1000mm focal length using a 10mm eyepiece is operating at 100x magnification (1000/10=100).