. In the charity shop today there was a meagre choice of two binoculars. A 10×25 roof prism at 4 pounds and a 4X Soviet at 6 pounds.
I chose the 4 times.
It is marked Made in the USSR on the front hinge and 4X on the rear right-hand side. On the rear left-hand side is a triangle within a circle with the capital C in the middle. I cannot remember the maker, possibly Lomo?
The strange thing is how well made and slightly complex the instrument is.
I partially dismantled it and the front objectives are triplets. Composing a cemented doublet and a single element. All surfaces are nicely multicoated, and in typical Soviet fashion the large front objectives have different colour coatings. One is mauve and the other is a yellowish mauve. There is a just discernible difference when looking through the two barrels regarding colour cast.
The front cell is complex in that there is a specially shaped rear cone section with a field stop at the back.
There is a central focus wheel at the front of the binocular on the front hinge. It is an internal focus mechanism and the instrument does not change size when focusing.
The focusing elements seem small and near to the eyepiece. All surfaces are multicoated. I think the rear may be composed of a single focusing element and an achromatic doublet behind it making three elements in all.
So there are six lens elements in total on each side.
The front aperture is 36 mm, maybe 36.5 mm.
So this is a 4×36 opera glass.
It is mainly made of metal, maybe aluminium, steel and brass with leather trimming and plastic eyecups.
There is no dioptre correction, and I need this as my eyes differ by 1.5 dioptres. However, everything is beautifully machined and there are shims et cetera. So I have just unscrewed one of the front outer cells to exactly suit my eyes. This seems to work okay.
The central resolution is good, but the edge performance is not. And even without glasses the field size is only 5° or 6°. I will measure this.
So the question to ask is. Why did they make this instrument?
The 4×22 China made binocular has a field of 16.5°. The China binocular is a much later instrument than the Soviet four times instrument, which probably dates from about 1980. Admittedly the Soviet instrument is compact.
It comes with a good quality leather case and well worn leather strap. The leather is marked inside OTK 9?-22. The instrument has seen quite a bit of use and also the leather edges are slightly coming away from the metal.
. Maybe somebody has some more information about this instrument. It certainly is not much use for birdwatching, but I will try it on the stars.
P. S.
I'm not sure if you can have a field stop in Galilean binoculars. Perhaps it should be called a ray shield or some other name?
I chose the 4 times.
It is marked Made in the USSR on the front hinge and 4X on the rear right-hand side. On the rear left-hand side is a triangle within a circle with the capital C in the middle. I cannot remember the maker, possibly Lomo?
The strange thing is how well made and slightly complex the instrument is.
I partially dismantled it and the front objectives are triplets. Composing a cemented doublet and a single element. All surfaces are nicely multicoated, and in typical Soviet fashion the large front objectives have different colour coatings. One is mauve and the other is a yellowish mauve. There is a just discernible difference when looking through the two barrels regarding colour cast.
The front cell is complex in that there is a specially shaped rear cone section with a field stop at the back.
There is a central focus wheel at the front of the binocular on the front hinge. It is an internal focus mechanism and the instrument does not change size when focusing.
The focusing elements seem small and near to the eyepiece. All surfaces are multicoated. I think the rear may be composed of a single focusing element and an achromatic doublet behind it making three elements in all.
So there are six lens elements in total on each side.
The front aperture is 36 mm, maybe 36.5 mm.
So this is a 4×36 opera glass.
It is mainly made of metal, maybe aluminium, steel and brass with leather trimming and plastic eyecups.
There is no dioptre correction, and I need this as my eyes differ by 1.5 dioptres. However, everything is beautifully machined and there are shims et cetera. So I have just unscrewed one of the front outer cells to exactly suit my eyes. This seems to work okay.
The central resolution is good, but the edge performance is not. And even without glasses the field size is only 5° or 6°. I will measure this.
So the question to ask is. Why did they make this instrument?
The 4×22 China made binocular has a field of 16.5°. The China binocular is a much later instrument than the Soviet four times instrument, which probably dates from about 1980. Admittedly the Soviet instrument is compact.
It comes with a good quality leather case and well worn leather strap. The leather is marked inside OTK 9?-22. The instrument has seen quite a bit of use and also the leather edges are slightly coming away from the metal.
. Maybe somebody has some more information about this instrument. It certainly is not much use for birdwatching, but I will try it on the stars.
P. S.
I'm not sure if you can have a field stop in Galilean binoculars. Perhaps it should be called a ray shield or some other name?
Last edited: