8x42 Binoculars

What does 8x42 mean?

The first number is the magnification: a robin 40m away looks as if it were 5m away. The second is the diameter of each objective lens in millimetres, which decides how much light gets in. Divide 42 by 8 and you get the exit pupil, 5.25mm, the width of the beam of light that reaches your eye. That is generous: it fills a dilated pupil on a dull winter afternoon and makes the view easy to line up, so you spend less time hunting for the image and more time on the bird.

Two other numbers are worth knowing for general birding. The twilight factor (the square root of magnification times lens size) is 18.3, a rough guide to how much detail you can make out in poor light. And field of view, the width of the scene at 1,000m (often written as 142m/1000m), usually sits between 125m and 143m on a modern 8x42, wider than almost any 10x pair. The RSPB's guide to binocular terms explains the rest of the numbers on the box.

Why 8x42 binoculars suit most birders

Ask a room of birders which one pair of binoculars they would keep and most will say an 8x42. It sits in the middle of every trade-off:

• A wide field of view. Warblers flit, kingfishers skim past and a sparrowhawk is gone in seconds. A wider field makes it quicker to find a moving bird and easier to stay with it.
• Brightness in poor light. Birds are busiest early and late, often under trees. The big exit pupil keeps the image bright and forgiving when an 8x32 starts to look dim.
• A steadier image. Eight times magnification shows hand shake less than ten times, so the view looks calmer and fine plumage detail is easier to read.
• Comfort all day. At 640g to 750g for most pairs, an 8x42 sits on a neck strap or harness through a full day at a reserve without much strain.

That versatility is why the Cornell Lab of Ornithology called full-size 8x42s the most popular and versatile binocular style of the last couple of decades, and tested 30 of them for its affordable 8x42 review.

8x42 vs 10x42, 8x32 and 10x50

The same maker usually builds a series in several sizes with the same glass, so the choice is about how you watch, not quality.

Pick the higher magnification of a 10x if most of your watching is at range: waders on the mud or ducks on the far bank of a reservoir. Pick an 8x32 if you walk a long way and want to save 150g to 200g, accepting less brightness at dusk. The bigger 10x50 binoculars gather more light for the night sky but are heavy to carry far. If you are unsure, start with an 8x42; you can add a spotting scope later when distance becomes the limit.

Compare every 8x42 on this page

All share the same magnification, lens size and 5.25mm exit pupil, so the differences come down to glass, field of view, eye relief, build and cover. Specs are from each maker's listing; prices move daily, so check the cards above for today's figure.

The Endurance and Frontier pairs come in black, green or grey and the GPO Passion ED in black, green or brown, with identical optics in each finish.

What to look for in an 8x42

• Extra-low dispersion lenses. ED elements cut chromatic aberration, the purple edge round a gull against a bright sky. All but the Frontier HD X have them, which is why it costs less than its ED X sibling.
• Prism coatings. Phase-corrected roof prism glass sharpens the image and lifts contrast, while dielectric mirror coatings and fully multi-coated lenses raise light transmission, which shows on a grey day.
• Field of view. Most here show 140m or more. The Kowa BD II leads at 143m; the Bresser and GPO Passion HD are narrowest at 125m.
• Eye relief for glasses. Spectacle wearers need about 17mm or more to see the full circle with the eyecups twisted down. The Celestron Regal gives 22.5mm and the RSPB HD 20.3mm.
• Body and heft. Magnesium bodies (Kowa, GPO, Celestron, Frontier) are stiff and light; the polycarbonate Endurance keeps the price down. The Bresser at 636g and Kowa at 640g are the easiest to carry.
• Weather sealing. All are waterproof and fogproof, nitrogen filled or argon purged, so they won't mist inside when you step out of a warm car. The Frontier HD X carries an IPX7 rating.
• Tripod socket. The two Celestron pairs are tripod adaptable and screw onto a standard tripod adapter, handy for long sessions over water or for stargazing. Check the listing for the others.

Best picks at each budget

Under £300: the Hawke Endurance ED, Viking Merlin ED and Bresser Pirsch ED all bring ED lenses to entry money. The Endurance focuses down to 2m, handy for butterflies and dragonflies, and it comes with a no-fault lifetime guarantee. The Merlin has the wider 142m view; the Bresser is the lightest pair on the page. Below this sit budget porro prism pairs like the Nikon Action 8x42: bright and cheap, but bulkier and not as well sealed.

£300 to £400: the busiest band and the best mid-range value for most people. The Celestron TrailSeeker ED was the overall top pick in the Cornell Lab test, with the Kowa BD II XD tied second alongside the Nikon Monarch M7, and the cheaper Nikon Monarch M5 also among its top picks. The RSPB Harrier X and HD come from the charity's own range, and the Engage EDX has EXO Barrier coatings that shed rain and fingerprints. Compare whole ranges on our Kowa binoculars, Celestron binoculars and Bushnell binoculars pages.

£400 to £750: the Osprey ED, RSPB Buzzard with field flattening lenses, and the 680g RSPB HDX. See all of them on RSPB binoculars and Viking binoculars.

£750 plus: the GPO Passion HD, heavier at 830g but with 19.5mm eye relief and GPO's water-shedding drop coating. More on GPO binoculars and Hawke binoculars. Above this, direct sellers like Maven come in, with Maven's B1.2 at around £900, and alpha glass such as the Zeiss Victory SF or Vortex Razor runs to well over £1,500.

Where an 8x42 works best

• Woodland and hedgerows: the wide view and bright image are made for small birds moving through leaves.
• Reserves and hides: enough reach for ducks and waders on the scrape, and steady over a long session. The RSPB reserves finder lists hides near you.
• Garden and wildlife watching: blue tits on the feeder, buzzards over the field, deer at the wood's edge.
• Stalking and hunting: fine at dawn, though the bigger lenses on our hunting binoculars page help in the last light.
• Astronomy: a good grab-and-go pair for the Moon and star clusters; dedicated astronomy binoculars go bigger.
• Travel and birding trips: an 8x42 and its case pack into a day bag, but for a pocket choose compact binoculars.

Setting up your binoculars

Three adjustments make any pair look sharper. First, fold the barrels until you see one round image, not two overlapping circles. Second, set the eyecups: twisted up if you don't wear glasses, down if you do. Third, set the dioptre: close your right eye and focus on something with the centre focus wheel, then close your left eye and turn the dioptre ring, usually on the right eyepiece, until it is sharp too. Note the setting, and from then on you only need the centre wheel. The Which? binoculars buying guide has more tips on trying a pair before you buy.

Frequently asked questions

Are 8x42 binoculars good for bird watching?

Yes, they are the standard choice. The wide view, bright image and steady handheld picture suit woodland, gardens, reserves and mixed countryside. Only if most of your birds are far off, on estuaries or moorland, is a 10x worth the narrower view.

Is 8x42 or 10x42 better?

For one pair to do everything, 8x. It shows a wider scene, is easier to hold still and is a touch brighter at dusk. A 10x shows more detail on distant birds. In the same series the two sizes usually weigh within 20g to 30g of each other.

Are they good for glasses wearers?

Most are. Twist the eyecups fully down and look for 17mm or more of eye relief in the table above; every pair on this page has at least that, and the Celestron Regal has the most.

Can you use an 8x42 for stargazing?

Yes. The 5.25mm exit pupil makes them bright enough for the Moon, the Pleiades and the Milky Way. Rest them on a wall or fit a tripod adapter to keep the stars still.

Is the big exit pupil wasted as you get older?

Partly. Our pupils open less with age, so a 5.25mm beam may be slightly larger than an older eye can use in the dark. In daylight it still makes the view easier to line up, which is why the size suits everyone.

How much should I spend?

For regular use, from about £270. That buys ED glass, coated prisms, proper waterproofing and a long guarantee. Spending more mainly adds image quality: a wider, flatter view, better colour and lighter bodies. If that is the case for you, the £400 to £750 band is where the gains show.