Field Stop

_{Last Updated: Thu Apr 16 13:27:09 -0400 2009}

Q: What is the Field Stop?

A: Built in to an eyepiece is a circular metal ring or “mask” that defines the visible field of view in the eyepiece.

The angular diameter of this (visible) circle is the called the apparent field of view (AFOV), which is a set property of the eyepiece, by design.

The field stop diameter is measured in (mm).

_{Tags:
Eyepiece}