How to Choose a Finderscope: Red Dot vs. Optical

The finderscope is the unsung hero of telescope observing. Without a good finder, pointing your main telescope at a specific star or planet involves frustrating guesswork. With the right finder, you can reliably aim at any object in the sky in seconds.

Here's how to choose between the two main types: red dot finders and optical finderscopes.

Red dot finders project a red LED dot on a glass lens — keeping both eyes open while aiming.

Red Dot Finders (Reflex Finders)

A red dot finder (also called a reflex finder) projects a small illuminated red dot (LED) onto a partially reflective lens. Looking through it with both eyes open, you see the red dot superimposed on the sky. Place the dot on your target and look through the main eyepiece — the object should be there.

Pros:

• No magnification — the sky looks exactly as it does to the naked eye, just with a red dot for aiming
• Both eyes remain open — better situational awareness
• No image flip or inversion to confuse you
• Easy to use in the dark without dark adaptation
• Very accurate when properly aligned

Cons:

• No magnification means faint stars you can't see with the naked eye aren't visible in the finder either
• Requires a battery (LED)
• The red dot can be hard to see in bright twilight

Optical Finderscopes

An optical finderscope is a small telescope (typically 5x25 or 8x50) mounted alongside the main scope. It gives you a magnified view of the sky — wider than the main eyepiece, making it easier to identify star fields and star-hop to your target.

Pros:

• Shows fainter stars than the naked eye — useful for star-hopping to faint targets
• No batteries required
• Larger field of view at magnification lets you identify star patterns

Cons:

• The view is often reversed or inverted, which confuses beginners
• Requires dark adaptation to use comfortably
• Slightly more complex alignment

Which Should You Choose?

For beginners: Start with a red dot finder. The intuitive operation (what you see is what you get) makes targeting much easier in the early stages when you're still learning the sky.

For experienced star-hoppers: An optical finderscope (particularly a 9x50 right-angle version with a correct-image prism) is the preferred choice. The magnified view shows faint stars that help you navigate to challenging targets.

Many astronomers use both: A red dot for quick pointing, an optical finder for precise star-hopping to faint objects.

Browse our telescope accessories collection for compatible finder options for your scope.

An optical finderscope provides a magnified wide-field view to center objects before switching to the main eyepiece.

Frequently Asked Questions

What is the difference between a red dot and optical finderscope?

A red dot finderscope projects a red LED dot onto a glass lens — you look through it with both eyes open and place the dot on your target. An optical finderscope is a small magnifying telescope (typically 5x or 8x) that shows a wider field than the main scope, helping you center objects.

Which type of finderscope is better for beginners?

Red dot finders are generally better for beginners — easier to align, require no dark adaptation to use, and let you keep both eyes open for better situational awareness. Optical finders give a wider magnified field but often present a flipped view, which confuses beginners.

How do I align my finderscope?

In daylight, point your telescope at a distant object and center it in the main eyepiece. Adjust the finderscope bracket screws until the same object is centered in the finder (or the red dot is on it). Recheck alignment at night on a bright star. Realign if the telescope is bumped or transported.

Can I upgrade my telescope's finderscope?

Yes — most telescopes use a standard bracket system. Popular upgrades include the Telrad (a zero-magnification bullseye finder) and larger 9x50 optical finders. Browse our telescope accessories collection for compatible finder options.