Observing Equipment

A filter that blocks unwanted light — the orange glow of light pollution, or all but a single emission line such as hydrogen-alpha — so that faint nebulae stand out against the background. Filters let observers under city skies see what would otherwise be washed out.

The most-recommended first instrument in astronomy — wide-field, portable, and forgiving. A modest pair shows the craters of the Moon, the moons of Jupiter, star clusters, and the brighter galaxies and nebulae, and teaches the sky better than any telescope rushed into too soon.

From a standard camera to a cooled, dedicated astronomical one, the imaging heart of the hobby. Stacking many long exposures, an amateur camera reveals colour and faint structure in nebulae and galaxies far beyond what the eye can see at the eyepiece.

A large reflecting telescope on a simple, stable, inexpensive alt-azimuth mount — the design that put big apertures within reach of ordinary observers. It offers more light-gathering power per unit cost than anything else, and is the classic instrument for deep-sky observing.

A telescope mount tilted to align with Earth's rotation axis, so that a single, steady motion cancels the turning of the sky. It keeps an object centred as the Earth spins, which is what makes long-exposure astrophotography possible.

A small, portable motorised mount that slowly turns a camera to follow the stars, so that long exposures capture faint detail without the stars trailing into streaks. It has made wide-field astrophotography of the Milky Way accessible to anyone with a camera.