Diagonal mirror
# Diagonal mirror

A diagonal mirror is a flat mirror used to produce a right-angle bend in a light path. Examples of diagonal mirrors include:

* The secondary mirror used in a Newtonian telescope
* The tertiary mirror used in a Nasmyth telescope
* A star diagonal right-angled telescope eyepiece mount
* An optical Edwardian parlour entertainment device also known as a Zograscope
