Pocket Metal Zoom Monocular 25mm, Phone Adaptable

See what is out there before you drive out there.

You are stopped at the top of a ridge looking at a track a couple of kilometres off, and you cannot tell from here whether it is a graded road or a washed-out gutter. Driving down to find out costs you an hour and half a tank, and if it is the gutter it costs you a lot more than that.

A monocular is the cheap way to answer that question from where you are standing. This one is a 25 mm pocket optic in an all-metal barrel that collapses to 129 mm and weighs 108 g, so it lives in the console rather than the camping box, and it takes a phone clamp so you can show someone else what you are looking at.

It is sold everywhere as a 10-300X, and we are not going to repeat that number as though we had measured it. The supplier engraves its own field of view on the barrel: 3.5° at 10X and 2.0° at 300X. Field of view narrows as magnification rises — that is how optics work — so a view that barely narrows across the whole range is not describing a thirty-fold change in power. Everything the supplier actually prints is in the Specs tab. Everything we could not confirm is in Limits, including that number.

What It Does

• Pulls the distance in: brings a far-off track, fence line, gate or roof close enough to judge before you commit the vehicle to it.
• Rides in the console: 129 mm collapsed and 108 g, so it goes in a door pocket or a shirt pocket instead of a camera bag.
• Extends to zoom: the barrel stretches from 129 mm out to 204 mm as you wind the zoom ring through its range.
• Focuses in close: the supplier leaflet gives a focus range from 35 cm out to infinity, so it doubles as a close-up glass for tracks, plants and insects.
• Takes a phone: a clamp holds a phone camera over the eyepiece so you can photograph or film what you are seeing.
• Sits on a tripod: the body carries a threaded tripod socket, which matters more here than it sounds — see Limits.

Key Features

• 25 mm objective: the supplier parameter panel states a 25 mm objective lens and a 12 mm eyepiece. That is the front glass, and it is what sets how much light the thing gathers.
• BAK-4 roof prism: the panel names BAK-4 glass in a roof-prism layout, which is the better of the two prism glasses commonly used at this end of the market.
• Multi-coated glass: stated as a multilayer coating — broadband green film on the objective, blue film on the eyepiece.
• All-metal barrel: the supplier states an all-metal body. The specific alloy is not stated anywhere on the artwork.
• Distance scale: the inner barrel is engraved with a focus scale marked 0.5, 1, 2, 5, 8 and infinity, so you can preset roughly where you want it.
• Damped focus ring: the focus and zoom rings are knurled metal with a damped feel rather than free-spinning plastic.
• Tripod socket: a threaded tripod interface is fitted. The supplier does not state the thread size.
• Pouch and cloth: a padded nylon belt pouch, a lens cloth and an instruction leaflet are shown in the packaging photographs.

Limits

The magnification number is not a specification

Read this part first. It is the whole reason this listing is worded the way it is.

The supplier prints its own angular field of view on the barrel: 3.5° at 10X, 2.0° at 300X. Field of view and magnification move in opposite directions and roughly in proportion — wind the power up thirty times and the view through the glass has to close down by something like the same factor. These two printed figures barely move. Whatever the barrel is doing between its stops, the supplier's own numbers do not describe a thirty-fold zoom, and we will not publish one.

There is a second body in the supplier photographs engraved 10-300X40mm, 4.6° at 10X, 2.6° at 300X — a different objective marking and a different field of view, showing the same pattern. We cannot tell you which body ships against which option, and we have said so in the Q & A rather than guessing.

What you should expect instead: a small 25 mm optic will show you useful detail on a distant gate, vehicle, track or animal well beyond what your eye does. It will not read a number plate across a valley. Above roughly the low teens of magnification, no handheld optic of any price is steady enough to use without support — your pulse alone moves the image more than the detail you are trying to see. That is why the tripod socket matters and why it is worth using.

"HD 4K" does not mean what it looks like it means

An optical monocular has no sensor, no processor and no resolution. There is nothing in it that could be 4K. The phrase comes from the supplier's own artwork, where it is applied to the lens coating — the panel reads "4K FMC coating". It is a marketing word attached to a piece of glass, not a video specification, and it says nothing about what your phone will record through it. We have taken it out of the title for that reason.

Other things it will not do

• Not weather rated: no IP or IPX rating is printed anywhere on the product or the supplier artwork, and no nitrogen purging or fog-proofing is claimed. Treat it as a dry-weather instrument, keep it in the pouch in the wet, and expect it to fog on a cold morning.
• Not an astronomical instrument: the box is printed with the word telescope and the marketing photographs are staged against the moon. It is a hand-held monocular with 25 mm of front glass. Do not buy it to look at planets.
• Not a low-light optic: 25 mm of front glass is a small light bucket. At dawn, dusk or under trees the image goes dim quickly, and it does nothing at all in the dark.
• Not a phone zoom lens: a phone clamped over an eyepiece is fiddly to line up and vignettes easily. It works, but it is a two-handed job on a tripod, not something you do quickly from the driver's seat.
• No eye relief figure: the supplier does not state eye relief or exit pupil. If you wear glasses to view, we cannot tell you in advance whether you will get the full field.

Q & A

So will it actually zoom to 300 times?

We do not believe so, and we are not prepared to publish the number as if it were measured. The supplier's own engraved field of view moves from 3.5° to 2.0° across the range, which is not the behaviour of a thirty-fold zoom. It does zoom — the barrel extends and the image gets bigger. We cannot tell you by how much, because nothing printed on or with the product supports the figure on the box.

Then why is 10-300X still on the barrel and in the specs?

Because it is physically engraved on the product and you will see it when it arrives. We would rather show you the marking, tell you it is a marking, and let you decide, than quietly delete it and have it turn up in the post as a surprise.

Does it come with the tripod and the phone clamp?

There are two options on this listing and the supplier's packaging photographs show two different kits — one with the phone clamp and mini tripod, one without. The supplier does not label which option is which, so we cannot confirm it from here. If the clamp and tripod are the reason you are buying and the wrong one arrives, that is a not-as-described return and we will sort it out.

Can I use it in the rain?

No rating is printed, so we cannot say it is sealed. Wipe it dry, keep it in the pouch when it is wet, and do not submerge it. A cold barrel brought into warm humid air will fog internally and there is no purge gas stated to stop that.

How close will it focus?

The supplier leaflet states 35 cm to infinity, with a note that between 50 cm and 35 cm you need to extend the objective barrel to bring it in. The engraved distance scale runs 0.5, 1, 2, 5, 8 and infinity.

How long does delivery take?

Allow 10 to 14 days from the day you order, and up to three weeks to be safe. Regional and remote addresses take longer again. Delivery is free to Australia and New Zealand.

Specs