RF-4
lens for duplicating camera FKR, 770984
360 mm, 1:10, M60
LOMO, Leningrad, USSR

Perfect condition. Lens is clear and clean, without any fungus. Rear glass has tiny cleaning microscratches. Inside the lens there is some microdust. Body has small signs of age. Aperture works properly and tightly. 

This is a large format lens for duplicating camera FKR. It's one of the best USSR lenses for large format cameras.
Camera FKR was used in polygraphic industry. It's frame size was 30x40 cm and lens RF-4 was used with special frame 24x30 cm.
Lens RF-4 replaced Industar-11 having much better resolving power.

This lens does not have focusing ring. Focusing is achieved with moving of the camera body. Thanks to the lens sharpness enlarger was used to reproduce books, newspapers, drafts, manuscripts and so on.

This lens is interesting with a cut at the body. Additional diaphragm of necessary shape (square, rectangular, hexagonal and so on) can be inserted through that cut.

Lens has one-layered anti-reflection coating.

Characteristics: 
Lens s/number - 770984
Number of lenses - 6 in four groups
Frame size - 24x30cm
Number of aperture blades - 12
Angle of view - 43o
Limit of aperturing - 1:10 (max), 1:64 (min)
Type of mount - M60x0.75
Resolving power - (centre/edge) 35/17 lines/mm
Dimensions (mm): 87*87*70
Mass - 417 g