Agat-18 was produced at several BelOMO enterprises from 1984 to 1989. The Agat line consisted of only two devices, the second was Agat-18K. Why did the device immediately receive an index of 18? I would venture to suggest that this is from the size of the short side of the frame 18 mm, i. The index covertly indicates that the device is half-frame. A semi-format camera is a camera designed for a standard 35 mm film, but displaying half the size of frames on it. Not 24×36 mm, but 24×18. It is quite unusual, although it is quite obvious that the horizontal position of the frame in a half-format device is achieved with the vertical position of the camera itself. The advantage of this concept is the fact that it is possible to fit not 36, but 72 frames on a standard film. In the USSR, from the 60s to the end of the 80s, in general, many models of semi-format devices were produced.