In order to more easily locate objects in a telescope, astronomers use reflex finders and/or optical finder scopes. These devices show a wide area of sky and have either a red dot or a crosshair in the center, indicating exactly where the main telescope is pointed.
Reflex finders use lightly tinted window. In the center of the window is projected a small illuminated dot or reticle indicating where the telescope is pointed. With the multi-reticle finder the user can select a dot, crosshair or circle pattern by switching a lever.
Optical finder scopes are like a very small telescope. They magnify only a small amount and show several degrees of sky, making it relatively easy to locate the desired object. Optical finder scopes also use an objective lens which gathers more light than a reflex finder. You will see more when looking through an optical finder scope making it easier to spot dimmer objects.
