Binoculars are an ideal instrument for studying the night sky and should be in every astronomers arsenal. They have important advantages over telescopes - for example they are cheaper, smaller, easier to use and more versatile. Basically binoculars collect more light than your eyes, making dim objects brighter and giving some magnification. They can reveal planets and moons and give access to all kinds of deep space objects.


Binocular Descriptions

Binoculars bear inscriptions such as '10x50' and '7x40'. The first number refers to the magnification (eg) 10 or 7 times. The second number gives the diameter of the larger objective lens in millimetres (eg) 50mm or 40mm, which relates to its light-gathering power.

Recommended sizes for astronomy are 7x50 or 10x50

Projects With Binoculars


First turn the central wheel until the binoculars give their sharpest image (this may be helped by shutting your right eye) then while keeping your left eye shut, gently turn the focusing ring on the right eyepiece until focus is perfect. Stars should appear as tiny pinpoints with both eyes open.


If binoculars show rainbow colours around a bright light source, the optics are poor quality. If images like stars appear double with both eyes but single with one eye, they are out of alignment. In either case, do not buy or take back to the seller.

Binocular Shake

One problem of hand-held binoculars is that they magnify the natural muscular movement of your hands and make the stars dance around. To minimise shake, brace your arms or elbows on something solid like a wall or fence.

Binocular Mounts

A mount converts binoculars into an astronomical instrument. A good camera shop will sell you an adaptor that fixes binoculars to a camera tripod. The tripod controls allow you to move and lock the binoculars in position.

Binoculars and the Night Sky

Star clusters, nebulae, galaxies, our Moon are ideal subjects for binoculars they are an excellent gateway to the stars.