Worlds of David Darling
Encyclopedia of Science
   
Home > Encyclopedia of Science

field of view



  1. The angular size of the actual patch of sky being viewed by an instrument (usually less than 1°).

  2. The apparent size of the field stop as seen through an eyepiece (20° to 90°, depending on the eyepiece). The actual field of view is the angle, measured on the sky, from one edge of the eyepiece field of view to the other; approximately equal to the apparent field of view divided by the magnification. The apparent field of view is the field of view that is written on eyepieces. To get the true field of view, the apparent field must be divided by the magnification of the telescope.

Related category

   • OPTICS AND OPTICAL PHENOMENA