## Telescope Terms

11.19 - Understand that the ‘light grasp’ of a telescope is directly proportional to the area of the objective element and thus the square of the diameter of the objective element11.20 - Know that the aperture of a telescope is related to the diameter of the objective element

11.21 - Know that the field of view is the circle of sky visible through the eyepiece, measured in degrees or arcmin

11.22 - Understand the resolution of a telescope is:

a) proportional to the diameter of the objective element

b) reduced by observing at a longer wavelength

11.23 - Be able to use the formula for the magnification of a telescope:

__= magnification__

*f*_{o}*f*

_{e}where

*f*is the focal length of the objective element and

_{o}*f*is the focal length of the eyepiece

_{e}Much of this terminology applies to any kind of Telescope or seeing device. I'm part of the 'I love binoculars' fan club myself.

See the following pages for information on these terms: