tento 12x40 (1 Viewer)

[publin]

HI! is someone familiar with this russian vintage bino? optic qualitiy? bak4 or bk7 prism? F.O.V ?

 

[Stephen Prower]

Tento 12x40

Publin

I use one.

The Zomz 12x40 is a model by the manufacturer who I believe makes the 12x40 that is marketed by Tento. The Tento is I believe, from its construction, a later model. The two models have a similar basic design, and probably also, given the conservatism of the Soviet/Russian optical industry, similar optics. The quality of the external finish of the Tento is inferior, to my eyes, to the quality of finish of the Zomz.

Holger Merlitz gives the FOV of the Zomz 12x40 as 5.6* (ie 67* apparent FOV). Zomz's literature as recited by Allbinos specifies the FOV of the Zomz 12x40 to be 6* (ie 72* apparent FOV).

Binastro may be able to help more.

The Zomz 12x40 has a high reputation with posters on Bird Forum and Cloudy Nights. I believe the Tento 12x40 is also well spoken of. I use it in the field, and find it very good ergonomically and optically. The weight is 854g. My glove size is medium to large. The Tento might not suit so well someone with small hands.

I can't help re prism glass or coatings. The Tento, by virtue of its probably more recent date, could well have better coatings than the Zomz. I have not, however, compared the Tento and the Zomz optically side by side.


Stephen


[I forgot to mention the focusser, often the weak spot certainly of a Soviet binocular. On my Tento 12x40 the focusser turns very freely, almost loosely. But it nevertheless turns regularly, so that I find its movement to be acceptable]

 

[Binastro]

I have two ZOMZ 12x40.
These have different eyepieces, which were revealed by accurately weighing both binoculars.
Then measuring the eyelens rear aperture, one is slightly bigger than the other.
It may be the earlier one is better, but I cannot remember.

I made the field with both to be 5.8 or 5.85 degrees from memory, but short eye relief, so some may struggle to see the full field.

With one the prism had moved causing misalignment, then for a while if fell back into place and gave good views.
Later it was misaligned again.

However, I prefer the 12x45 Russian binocular. I used the best of six for ten years as my main binocular. It is beautifully balanced and easily outresolves a Nikon 10x35 EII hand held.
The transmission is not high and it has a yellowish cast, but this doesn't bother me. The field is about 5.4 degrees. It is still in good alignment and still gives good views.

I am not sure if I had a Tento 12x40, I'll look it up.

Regards,
B.

 

[Binastro]

Just got one of the 12x40s.
Amazingly it has coated posssibly multicoated prisms and amber coated other surfaces.
The rear eyelens surface is uncoated, probably deliberately.
One objective surface uncoated, maybe the softer glass rear element.
This is a high quality product.
This one is made in 1978.
Almost clear front and back caps.
Leather case containing two eyepiece filters.
Cyrilic BIN2 12x40
MADE IN USSR
Very good condition.
Black leather? covered body.
Front and rear black.
Exit pupils round at all angles.

I can see the whole field if my eyes are close, but it has fairly deep metal eyecups.

Dioptre marked +/-3 but goes to about +/-7.

I haven't looked at the second one yet, as the case strap is entangled with something else.

B.

P.S.
The Tento 12x40, at least some versions, have a quite different body.
Flatter, much longer barrels but shorter body.
Maybe smaller prisms.
At least some are marked made in USSR.

It may be the ZOMZ I have is made near Moscow, and the Tento at a different factory in Leningrad?

I may have a Tento 7x50?

 

[Binastro]

2nd ZOMZ 12x40.

Same body, same coating arrangement but some different colours to 1st binocular above.
This one marked cyrillic BIN 12x40. (So BIN 1 equivalent).
MADE IN USSR
Made in 1975.
Bigger eyepieces, bigger eyelens. (Better performance).
Also very good condition.
Maybe no caps, but leather case.

B.

 

[Binastro]

Both Zomz 12x40 have almost distortion free eyepieces with a lot of angular magnification distortion near the edges.
Both are high resolution.
The 1975 one is out of alignment, the 1978 one is well aligned.

I do not find the image in these 12x40 binoculars to be as relaxing as the 12x45 image, which I used for long periods hand held.

If the Tento 12x40 in Post #1 is in good condition, well aligned and not expensive, it should be O.K.

B.