Telescopes & Equipment

Cassegrain telescopes use a primary mirror that reflects light to a convex secondary mirror, which reflects it back thro...

Coma is an optical aberration in parabolic mirrors (like Newtonians) that makes off-axis stars appear as tiny comets poi...

Equatorial mounts align one axis parallel to Earth's rotation axis, allowing simple tracking of celestial objects with s...

A field flattener is a corrective lens that eliminates the curved focal plane inherent in many telescopes, producing sha...

Specialized filters block light pollution and enhance contrast for emission nebulae by isolating specific wavelengths.

Focal ratio is the telescope's focal length divided by its aperture (f-ratio = focal length / aperture diameter).

Go-To mounts use computerized motors and databases to automatically locate and track celestial objects, dramatically sim...

A guide scope is a small telescope piggybacked on the main imaging telescope, paired with a camera to provide real-time ...

A space telescope launched in 1990.

Light pollution filters selectively block wavelengths from artificial lighting (sodium, mercury vapor) while passing sta...

Maksutov-Cassegrain telescopes use a thick meniscus corrector lens instead of Schmidt's aspheric plate, creating compact...

The Newtonian design uses a parabolic primary mirror at the tube's base and a flat secondary mirror near the top to refl...

Schmidt-Cassegrain Telescopes (SCTs) combine a Schmidt corrector plate at the front with Cassegrain optics, creating a v...