GOZ KO-140 1:2,2 F=140mm Review
GOZ KO-140 1:2,2 F=140mm (Russian name ГОЗ КО-140 1:2,2 F=140 мм) is a cinema projection lens. Has “Petzval” optical design, which began the rapid development of portrait photography.
This copy has an aperture f/2.2, and is an earlier version. Later the lenses were made of KO-140M and 35KP-1.8/140mm with an aperture f/1.8.
Rumor has it that the lens is a copy of Zeiss Kipronar 2.2/140mm projection lens. True it or not, there is no way to check.
The lens has an impressive size. but relatively light, because the lenses group are in front and behind, in middle is an empty tube. It disassembled piece by piece.
Dissassembled KO-140 1:2,2 F=140mm
The “Petzval” optical design is characterized by curvature of field, which makes an lens, interesting for artistic photography. But using it requires skills.
KO-140 1:2,2 F=140mm Specs
Focal length (mm): 140
Aperture: fixed f/ 2.2
Weight (gr): about 700
Length (mm): 180
Filter Ø (mm.): none
Front barrel Ø (mm.): 64,2
Rear barrel Ø (mm.): 62,2
Resolution (center/edge): 80/45
Mounting KO-140 1:2,2 F=140mm on DSLR Camera
This lens is difficult to mount to the camera, due to its huge size. The diameter of the rear barrel of 62.5 mm, so it is not easy to find such a focusing helicoid.
Is that from the mirror lens only, but is not easy to find it for parts. An example of such a construction.
I was still wondering what image it gives, and I mount it to the Nikon D3100 camera with a metal cup, from the chandeliers. I wasted a rear opening a file, and glued to the back of the adapter M42-Nikon, to attach it to the camera.
Flange focal distance of the lens is approximately 65mm, allowing it to set any camera retaining infinity.
Lens to fit snugly into the cup, I wrapped it with electrical tape, and took a primitive focusing mechanism of the “trombone”. This design is still viable, because you need to come up with a stopper, which did not allow lenses to fall out. But for a few test shots go.
KO-140 1:2,2 F=140mm Field Test and Sample Photos
All photos taken with the camera Nikon D3100. Raw export without postprocessing.
KO-140 1:2,2 F=140mm Sharpness
The lens is very sharp in the center of the frame, but because of the large aperture has a narrow depth of field. At the edge of the frame sharpness falls.
Example of sharpness at infinity
KO-140 1:2,2 F=140mm Bokeh
When a particular scenes can get beautiful bokeh. “Petzval” swirly bokeh I did not find, but may simply not find the right background.
KO-140 1:2,2 F=140mm Contrast and Color Render
The lens has a single coating. Very afraid backlight and side light, because of its design. May be a lens hood of partially save the contrast, but in general I do not like it.
KO-140 1:2,2 F=140mm is an interesting lens for artistic shooting, attracts the “Petzval” optical design and low price. But at the same time it is very difficult to mount to the camera to work properly.