By Joel Douglas
Updated Aug 30, 2022
Refracting telescopes use glass lenses housed in a metal tube to collect light from distant celestial objects—moon, planets, star clusters, and nebulae. When paired with interchangeable eyepieces, they reveal extraordinary detail. Compared to reflectors, refractors deliver superior optical clarity, making proper use essential.
Choose an observing location far from artificial light. Light pollution from porch lights, streetlamps, and other sources brightens the sky, obscuring faint objects.
Place the tripod on the ground. Extend each leg to equal length and secure with thumbscrews. Once upright, loosen the mounting bracket’s thumbscrews, insert the telescope, then tighten the retaining screws.
Loosen the finder scope mount’s thumbscrew, insert the finder scope, and secure with the retaining screw.
Point the telescope toward a bright target—moon or star. Raise or lower the tube and move it left/right to align with the target’s general direction.
Look through the finder scope. Adjust the telescope so the target is centered in the finder.
Insert a low‑power eyepiece (≤75× magnification) into the focuser and tighten. Verify the target is within the field of view; if not, re‑center using the finder. Fine‑tune the focuser knob until the image sharpens.
Swap to a high‑power eyepiece (>75×) for detailed study. Adjust the focuser until the target is sharp.
Consult the telescope’s manual to find its focal length. Divide that by the eyepiece focal length to compute magnification. For instance, a 600 mm telescope with a 10 mm eyepiece yields 60× magnification.
Observing the sun through a telescope will seriously damage your vision.
