RO2-2М 75 mm f/ 2
focal length 75.1 mm
angle of view 23°
flange focal distance 57 mm
back focal distance 48.94 mm
resolution 45 / 25 lpmm
diameter 60 mm
threaded attachment size 45 mm
optical transmission ratio 0.81
The RO2-2М 75mm f/2 is a fast prime lens, manufactured at the KMZ (Krsnogorsk Mechanical Plant). It is designed for professional 35 mm motion picture cameras with a 16x22 mm frame size.It came in the frame designed for the Konvas-avtomat camera (flange focal distance 57mm, frame diameter 47 mm).
The RO2-2М should not be confused with the RO2-2lens. The RO2-2М is an advanced variant, image quality is equal or superior to that of the Biotar 75mm. The RO2-2 was manufactured in Leningrad, whereas the RO2-2М lens was produced in Krasnogorsk (KMZ).
There are several versions of the lens:
1. The RO2-2 Kinooptika was manufactured in Leningrad from 1945 to 1948 by employing specially refined German optical glass. Manufactured: 1000 pcs. Due to manufacturing and polishing complexity the lens was discontinued. It had a limited use. It came with the AKS-1 camera only.
2. The RO2-2M was manufactured at the KMZ (Krasnogorsk). In 1948 a Leningrad plant conveyed the optical scheme and a polishing machine to the KMZ. Production years 1949 - 1950. Manufactured: 1500 pcs. It was designed for professional motion picture cameras. Due to high costs of manufacturing and a special chemical coating, the lens was discontinued. In 1951 the RO2-2 KMZ, a low-end lens, was put into production at the KMZ. The lens was not coated and therefore was not popular with cinematographers. Manufactured: 500 pcs. In 1951 two new affordable lenses were put into production: RO2-2p and RO2-2М p (p stands for coated). These lenses were produced by the piece. They featured a new violet coating. The new coating, as opposed from that of the RO2-2М, which rendered the image as it is, added tints of yellow to the image. Unfortunately, the lenses were not intended for ordinary customers and were in demand among professional photographers only.
If the RO2-M, as well as its analogs, featured an aperture of f/2, the RO2-2МP had an aperture of f/2.5.
The RO2-M lens was discontinued, as new lenses LOMO and Lenkinap were released. They employed the Biotrar/Gelios-40 optical scheme, were inexpensive and therefore in great demand.
The lens elements were chemically coated.
Its high light-gathering power and resolution make it possible to use the lens for shooting feature and sports movies, documentaries, etc. Due to a peculiar optical scheme, the lens delivers a magnificent individual image with a very effective bokeh.
The RO2-2М resolution - 45 lpmm at the center, 23 lpmm on the edges, which is superior to both the Gelios-40 and the Biotar 75 mm - 32 lpmm at the center, 16 lpmm on the edges.
The price for the RO2-2М may reach $ 650 in the Russian market and even $1,300 if it comes complete with an adapter for modern SLR cameras and if the lens is coated. At EBay this lens is priced at 1,000 EUR.
The lens is capable of covering the full frame, but with vignetting. Via adapters the lens can be used on SLR cameras. Unfortunately, vignetting is notable even on a cropped sensor. The lens cannot be used on full frame sensors.
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Posted by: Relayer Date of publication: 25.12.2011