Three ways to take aim at the sky. Left: Lensless peep sights suffice for small telescopes with wide fields of view. Center:/ Reflex sights project a dim red dot or circle on the sky, improving precision. Right: Finderscopes make more targets visible and enable the most precise pointing. But many models turn the sky upside down or are hard to use with eyeglasses on.

S&T: Chuck Baker

Until recently, all finders were themselves miniature telescopes. Today, more and more scopes are sold with so-called “unit-power” (1×) or “red-dot” finders. The Telrad was the first commercial finder of this kind, but many others have since appeared on the market.

Using one couldn’t be easier. Switch it on, and a glowing red dot or bull’s-eye target appears projected on the sky when you look through a little window. To aim your scope, all you have to do is move the tube until that the red dot sits on your desired sky object.

Observers often find that red-dot finders and traditional finderscopes complement each other — it doesn’t have to be an either/or situation. I find it convenient to use a unit-power finder to get the telescope pointed in the general area, and then zero in on my target with my normal finderscope.