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Telescope Eyepieces Guide: Types, Sizes and Choices
A plain-language guide to telescope eyepieces: focal length, field of view, eye relief, barrel size, common designs, and which ones suit planets, the Moon and deep sky.
Choosing a Telescope
Eyepieces & Finders
5 guides, starting with Telescope Eyepieces Guide: Types, Sizes and Choices.
Finder Scope for Telescope: Types and How to Choose
Compare red dot finders, reflex finders and optical finderscopes, including right-angle erecting types, and learn how to choose the best finder for your telescope.
How to Use a Finderscope on a Telescope
Step-by-step help for aligning and using a finderscope on your telescope, with fixes for upside-down images and for seeing nothing through the eyepiece.
Telescope Eyepiece Diameter and Barrel Sizes
Learn the standard telescope eyepiece barrel diameters (0.965, 1.25 and 2 inch), how they differ from focal length, and how to pick sizes that fit your focuser.
Telescope Eyepiece Magnification Chart and How to Use It
Use a telescope eyepiece magnification chart to match eyepieces to your scope: formula, two example charts, exit pupil and useful magnification limits.
Related topics
More in choosing a telescope
Telescope Types 7 guides, starting with Telescope Types Explained. Choosing a Telescope 6 guides, starting with How to Pick a Good Telescope: A Buyer’s Guide. Dobsonian Telescopes 5 guides, starting with Dobsonian Telescope for Beginners: Why It Is a Great First Scope. Telescope Optics & Specs 6 guides, starting with What Is Aperture on a Telescope? Why Size Matters. Telescope Filters 3 guides, starting with Telescope Filters Guide: Which Ones Are Worth Buying.