Boshile 20x50 Fixed-Focus Binoculars with Ranging Reticle

No focus wheel. Nothing sharp closer than 6 m.

Something shifts on the far ridge, you get the binos up — and then you spend the next four seconds winding a focus wheel back and forth while whatever it was walks off. Hand them to a mate and he does the same thing, then hands them back set for his eyes instead of yours.

On the water it is worse than an annoyance. If you cannot read a channel marker or make out what is on the deck of the boat tracking towards you, you are making a call on a guess, and on a moving deck the guess is the part that goes wrong.

These fix that by removing the adjustment entirely. The eyepieces are set at the factory to a deep depth of field, so everything from about 6 metres out to the horizon sits acceptably sharp and there is nothing to turn. Lift, look, done. That is genuinely quick, and it is genuinely useful when the binos live in the ute and get passed around.

The supplier calls this "autofocus". It is not. There is no motor, no sensor and nothing in there that focuses itself — an optical binocular has no way to do that. What it actually is is fixed focus, sometimes called focus-free, and that is a real design with real advantages. It also has a real cost: you cannot focus them nearer than 6 m, and there is no dioptre ring, so if one of your eyes is noticeably different from the other you cannot dial that out. We would rather call it what it is and let you decide.

The other thing worth knowing up front: 20x is a lot of magnification for a handheld pair. Braced on a bonnet, a fence post or a gunwale they are steady. Free-hand and standing up, they wobble.

What It Does

• Lift and look: no wheel, no dial, no setting up. Everything from roughly 6 m to the horizon is already about as sharp as it is going to get.
• Pulls distance in: 20x through 50 mm objectives, with the field of view marked on the body as 56 m at 1000 m.
• Carries a ranging scale: an etched coordinate reticle sits in the right barrel for judging distance and holdover against an object of known size.
• Lights the reticle up: a small lamp turns the scale red, amber or green after dark, with buttons for brightness and colour and a battery compartment on the left barrel.
• Shrugs off weather: the supplier photographs them wet and calls them "life waterproof". Rain and spray, not immersion — see Limits.
• Turns up ready: carry case, wide shoulder strap, lens cloth and instructions are all in the box.

Key Features

• 20x50 Porro prism: the classic offset-barrel shape, 20x magnification through 50 mm objective lenses and 24 mm eyepieces.
• Exit pupil 2.5 mm: that is the supplier's own figure and it is simple division — 50 mm of objective divided by 20x. It is the number that governs how bright the view is at dusk.
• Eye relief 20 mm: listed by the supplier as exit pupil distance. Generous enough that the eyecups can stay folded down for glasses.
• Near limit 6 m: stated by the supplier, and the honest edge of what a fixed-focus pair can do.
• Illuminated coordinates: the scale reads as plain etched lines in daylight and switches to red, amber or green under the lamp at night.
• Metal chassis: the supplier describes a metal structure under an anti-slip covering it calls a leather cover. The covering material is not specified.
• BAK-4 and multi-coating: both are stated by the supplier on its own artwork. Neither can be verified from outside the housing — see Limits.
• 788 g, army green: a proper full-size pair with a rubberised feel, in the green shown in every photograph on this page.
• Complete kit: binoculars, padded carry case with flap, wide shoulder strap, lens cloth, instruction sheet and retail box.

Limits

This is the section that matters on this product, because the name on the box is wrong and the price bracket is one where specifications get optimistic. Here is what these will not do.

• They do not autofocus: optical binoculars cannot. There is no motor, no sensor and no processor anywhere in the housing, and the supplier's own parts diagram labels no focus control and no dioptre ring. It is fixed focus, and the word on the artwork is marketing.
• Nothing under 6 m: the supplier states a near focus distance of 6 m. A bird in the next tree, an insect, a plant, anything across a small yard — all of it stays soft and no amount of fiddling will fix it, because there is nothing to fiddle with.
• No dioptre correction: if your left and right eyes need different focus, a fixed-focus pair cannot compensate. Most people get on fine. If you already know your eyes differ, a pair with a dioptre ring will suit you better.
• Handheld shake at 20x: the shake is magnified along with the view. Expect to brace them against something solid for anything longer than a quick look.
• Dimmer at dusk than 50 mm suggests: a 2.5 mm exit pupil is narrower than a relaxed human pupil in low light, so the big objectives do not translate into a bright twilight view. A 10x50 delivers 5 mm and will out-perform this at last light.
• The reticle is not a rangefinder: it is an etched scale you read against something whose size you already know. It does not measure anything, there is no laser and no electronics beyond the lamp.
• No water rating is published: the supplier prints "life waterproof" and a waterproof-construction badge, and no IP or ATM figure appears on the product or anywhere in its documentation. Treat them as water resistant against rain and spray. Do not submerge them and do not drop them over the side.
• Fog-proofing is unconfirmed: the artwork says anti-fog and anti-mildew, but no nitrogen or argon purge is stated. Sealed dry-gas filling is uncommon at this price, and without it a hard temperature swing can fog the inside of the glass.
• BAK-4 and FMC are claims: the supplier states both, on its own marketing panels, with no test certificate. Prism glass and coating quality are the two specifications most often overstated in this bracket, and neither can be checked without pulling the binoculars apart.
• The field of view figures disagree: the body is engraved 56 M AT 1000 M, while the supplier's parameter panel says 7.3 degrees. Those two do not describe the same instrument — 56 m at 1000 m works out at about 3.2 degrees, which is a normal figure for 20x. We have published the engraving because it is on the product itself.
• No tripod thread is stated: the supplier neither lists one nor labels one on its parts diagram. If you are planning to mount these, treat it as unconfirmed rather than assuming the socket is there.
• Not issued or approved kit: green paint and a ranging reticle are a styling choice and a feature, nothing more. No standard is printed anywhere on these and no test certificate was sighted. Nobody has approved them for any duty use.

Q & A

So there is genuinely no autofocus in there?

Correct. An optical binocular has no way to focus itself — there is nothing electronic in the light path. What the supplier is calling autofocus is a fixed-focus, focus-free design: the eyepieces are set once at the factory and the depth of field does the rest. Fast to use, but not adjustable.

How close can I actually focus them?

6 m, per the supplier's own parameter panel. Anything nearer than that will look soft and there is no control to correct it. If you want binoculars for birds in the garden or anything at short range, these are the wrong pair — go for something with a centre focus wheel and a close focus figure of about 2 m instead.

Do they need a battery, and is one in the box?

The optics work with no power at all. The battery is only for lighting up the ranging reticle at night. The supplier does not state the battery type, and no battery appears in its package-contents photograph, so plan on sourcing one once you can read the marking inside the compartment.

Can I take them out on the boat?

Rain and spray, yes — the supplier photographs them soaked and calls them life waterproof. Immersion, no. There is no IP or ATM rating published anywhere, so nobody can tell you what depth or pressure the seals hold, and these do not float. Use a strap and keep them out of the water.

Does the reticle tell me how far away something is?

Only by working it out. You match a known dimension — a person's height, a vehicle, a fence line — against the etched scale and read the distance off it. It is a manual method, not a measurement, and it is only as good as your estimate of the object's size. If you want a number on a screen, you want a laser rangefinder.

How long does delivery take?

10 to 14 days from the day you order, and allow up to 3 weeks. Regional and remote addresses run longer again. Delivery is free to Australia and New Zealand.

Specs