8x42 vs 10x42 binoculars: which should you buy?
Quick answer: both share a 42 mm objective, so the choice is really 8x versus 10x magnification. 8x42 gives a wider field of view, a steadier handheld image and a brighter low-light view (5.25 mm exit pupil), which is why birders and timber hunters favor it. 10x42 trades some of that for extra reach and detail on distant subjects, the reason it is the default for open-country and western hunting. If you cannot decide, 8x42 is the safer, more forgiving all-rounder; choose 10x42 when your glassing is mostly long-range.
Field of view: 8x42 is wider
Because 8x magnifies less, it shows a wider slice of the scene, roughly 393 feet at 1000 yards on a typical 8x42 versus about 330 feet on the 10x42 version of the same binocular. That wider view is a real advantage when you are trying to locate a small bird flitting through branches, follow a moving animal, or scan a hillside quickly. The 10x42's narrower view trades that ease of acquisition for a more magnified, detailed look once you are on the subject.
Brightness and low light: exit pupil decides it
Both sizes gather the same light through their 42 mm lenses, but they spread it differently. The 8x42 produces a 5.25 mm exit pupil; the 10x42 a 4.2 mm one (objective divided by magnification). In daylight your pupil is small, so both look bright. At dawn and dusk your pupil opens to around 5 to 7 mm, and the 8x42's larger beam fills more of it, so the image looks brighter at the exact moment game moves. If you hunt or watch wildlife in low light, that favors 8x42. (More on this in what binocular numbers mean.)
Steadiness: 10x shows more shake
Magnification amplifies your hand tremor along with the image. Most people hold an 8x view rock-steady; a 10x view visibly dances a little more, especially when you are winded, cold, or glassing for a long time. It is not a dealbreaker, but for extended sessions a 10x42 rewards a trekking-pole rest, a pack, or a tripod, while an 8x42 stays comfortable freehand.
Eye relief: often longer on 8x42
On many lines the 8x42 also offers a touch more eye relief than the 10x42 (for example about 17 mm versus 15 mm on the Vortex Diamondback HD). If you wear eyeglasses, that extra couple of millimeters is the difference between seeing the full field and a blacked-out, tunnel-vision edge, another nudge toward 8x42 for spectacle wearers.
8x42 vs 10x42 at a glance
| 8x42 | 10x42 | |
|---|---|---|
| Magnification | 8x (wider, steadier) | 10x (more reach) |
| Field of view | Wider (approx. 393 ft at 1000 yds) | Narrower (approx. 330 ft at 1000 yds) |
| Exit pupil | 5.25 mm (brighter low light) | 4.2 mm |
| Eye relief | Often longer (approx. 17 mm) | Often shorter (approx. 15 mm) |
| Hand shake | Easier to hold steady | Shakes more; likes a rest |
| Best at | Birding, timber, low light, all-day handheld | Open country, hunting reach, detail on distant subjects |
Which should you choose?
- Pick 8x42 for bird watching, timber and close cover, low-light glassing, all-day handheld use, or if you wear glasses.
- Pick 10x42 for open-country and western hunting, judging detail on distant or bedded game, and any glassing you do from a rest.
- Still unsure? 8x42 is the more forgiving all-rounder. But if you want one hunting binocular and often glass far, 10x42 is the popular default, our best binoculars for hunting picks lead with it.
FAQ
Is 8x42 or 10x42 better for bird watching?
8x42 is usually better for birding. Its wider field of view makes it easier to find and follow small, fast birds, the image is steadier in the hand, and the larger exit pupil (5.25 mm vs 4.2 mm) is brighter in shade and at dawn. 10x42 still works and gives more detail on distant or perched birds, but most dedicated birders prefer 8x42.
Is 8x42 or 10x42 better for hunting?
10x42 is the more common hunting choice because the extra magnification helps you judge antlers and pick apart distant, bedded game across open country. In thick timber or for fast, close shots, 8x42 gives a wider, steadier view. If most of your glassing is long and deliberate, choose 10x42; if it is close and quick, 8x42.
Does 10x42 really shake more than 8x42?
Yes, noticeably. Higher magnification amplifies your natural hand tremor along with the image, so a 10x42 view dances a little more than an 8x42, especially if you are tired, cold or braced awkwardly. Most people can hold 8x steady easily; 10x is fine for short looks but benefits from a rest or tripod for long glassing sessions.
Which is brighter in low light, 8x42 or 10x42?
8x42 is brighter at dusk. Both have the same 42 mm objective, but the 8x spreads that light into a wider 5.25 mm exit pupil versus 4.2 mm on the 10x. Since your pupil dilates to around 5 to 7 mm in low light, the 8x42 fills more of it, so the image looks brighter right at the end of legal shooting light.
Related: what binocular numbers mean · roof prism vs porro prism · how to choose binoculars · Vortex Diamondback HD 10x42 review · best binoculars for hunting 2026.