This is the seventh of a series of articles about astronomy equipment to help you decide what you might like. If you have questions about a specific piece of equipment, and how it compares to alternatives, send a note to me at and I’ll see what I can find out.

We have covered a lot of ground, but one item that we have not covered is a finder. Most telescopes need some kind of device to help you get close enough to an object so that it will be in the field of view of the telescope. There are basically three types of finders used with telescopes: a finder scope, a reflex sight, and a unit sight. Usually your telescope will come with one. This information is to help you determine if you want to add another type.

Finder Scopes: These are often quite small and may have a crosshair in it so you can tell when you have an object centered. Their size will be on the order of 6x30. Some have the ability to change the eyepiece so that you can have different magnifications (and fields of view) and you can even insert a lit-reticule eyepiece.

Reflex Sights: These are zero-magnification devices that superimpose a red dot or a red target on the field of view. This tells you when your object is properly centered. They are useful if you can’t find an object in a finder scope, or if you are using a smaller telescope. They are only useful for naked-eye objects.

Unit Sights: These may or may not have a cross-hair, but are the same as reflex sights without the red target or dot. They have no magnification, so are only useful for naked-eye objects.