Telescopes & Equipment

An altazimuth mount (alt-az) moves in altitude (up-down) and azimuth (side-to-side), like a camera tripod.

Aperture is the diameter of a telescope's primary light-collecting element (lens or mirror), the single most important s...

A Barlow lens is a negative (diverging) lens placed between telescope and eyepiece to multiply magnification, typically ...

Binoculars offer wide-field, two-eyed viewing ideal for casual astronomy, comet hunting, and surveying large sky regions...

A Dobsonian mount is a simple altitude-azimuth mount using Teflon bearings on a rotating base, revolutionizing amateur a...

An eyepiece is the small optical system at the telescope's focus that magnifies the image for viewing, essentially a sop...

A finder scope is a small, low-power telescope or sighting device mounted on the main telescope to help locate objects i...

Focal length is the distance from a telescope's primary lens or mirror to the point where light converges to form an ima...

Reflector telescopes use curved mirrors to collect and focus light, offering the most aperture per dollar.

Refractor telescopes use lenses to bend (refract) light to a focus, the classic "spyglass" design.

A star diagonal is a mirror or prism at 90° that redirects the light path, making viewing more comfortable by positionin...

A T-ring is a camera-specific adapter that attaches a camera body to telescopes via the standard T-thread (M42×0.75mm) m...