Buying guide

Binoculars for the night sky

Ask experienced observers what a beginner should buy and a surprising number say binoculars rather than a telescope. They are right, and the reason is not price. It is that binoculars get used.

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What the two numbers mean

7x50 means seven times magnification and fifty millimetre front lenses. The first number is how much closer things look. The second is how much light you collect, and as with telescopes, the second number is the one that decides what is visible. Divide the second by the first and you get the exit pupil in millimetres, which for 7x50 is 7.1mm, about as wide as a dark-adapted human pupil opens. That is not a coincidence; that ratio is why 7x50 has been the classic night glass for a century.

What you can actually see

Craters and mountain ranges along the lunar terminator, in detail. The four Galilean moons of Jupiter, visibly changing position from one night to the next, which is the observation that cost Galileo his freedom. The Pleiades resolved into dozens of blue stars rather than a smudge. The Andromeda Galaxy as an obvious oval glow. The Orion Nebula as a fuzzy patch with structure. Comets, which is what these particular binoculars are named for. Sweeping the summer Milky Way at low power is, for many people, the single best view in amateur astronomy, and no telescope can do it because no telescope has the field of view.

What to buy

Start here

Celestron Cometron 7x50

$45
7x magnification, 50mm objectives, 774g, handheld

The best first purchase in astronomy, and it is not close.

Seven power is low enough to hold steady for a whole evening and wide enough that you can actually find what you are looking for, which is the part beginners underestimate. Fifty millimetre objectives show craters along the lunar terminator, the four Galilean moons of Jupiter strung out in a line, the Pleiades filling the view, and Andromeda as a real smudge of light. They cost less than a tank of petrol.

The catch: They will not show Saturn's rings as rings. Nothing at this magnification will.

Check price at High Point Scientific
The step up

Celestron SkyMaster 15x70

$110
15x magnification, 70mm objectives, tripod recommended

The step up, once you know you like this.

Seventy millimetres at fifteen power turns open clusters into fields of individual stars and makes the larger nebulae genuinely structured rather than merely present. This is the size where a tripod stops being optional: handheld, your pulse is visible in the image.

The catch: Needs a tripod and an L-adapter, which is another thirty to eighty dollars.

Check price at High Point Scientific
For dark skies and a real tripod

Celestron SkyMaster 20x80

$160
20x magnification, 80mm objectives, 2.1kg, tripod required

The most aperture per dollar in binoculars, for people with somewhere dark to use it.

Eighty millimetres at twenty power is the practical ceiling before giant binoculars become a mounting project rather than an instrument. Under a dark sky this is a serious deep-sky tool, and using two eyes instead of one makes faint objects noticeably easier to hold.

The catch: Two kilograms. This is a tripod instrument, and the tripod needs to be a real one.

Check price at High Point Scientific

The trick that doubles what you can see

Brace them. Lean against a wall, sit in a reclining garden chair, or rest your elbows on a fence. Handheld shake costs you more detail than any optical difference between reasonable pairs at this price. A cheap pair braced beats an expensive pair held at arm's length, every time.

What to avoid

Zoom binoculars, where the mechanism costs you sharpness and light across the whole range. Ruby coated lenses, which are a marketing finish that throws away red light. Anything above 10x that you intend to hold, because your pulse becomes the limiting factor. And compact 8x25 models, which are excellent for birds in daylight and nearly useless after dark, because twenty-five millimetres gathers a quarter of the light of a fifty.

We do not currently earn anything from these links. Nobody pays to appear here. How we pick gear.