Soviet Russian Exponometer Leningrad 4 VINTAGE LIGHT METER for film cameras Analog light meter Photo light meter

Leningrad-4 Photoelectric exposure meter Appointment Photoelectric exposure meter "Leningrad 4" (U11 / 4) is designed to determine the shutter speed or relative aperture (aperture) when photographing in black and white and colored photographic materials. The light meter can be used for filming. The exposure meter can be used in bright sunlight and artificial light, in the open air and indoors. The photoelectric exposure meter consists of a selenium photocell, a meter with a scale and a calculator (calculator). The exposure meter has two measurement ranges for brightness and two for illumination. The measurement range is changed using an internal diaphragm controlled by a slide mechanism. To measure by illumination but in both ranges, the exposure meter window must contain a milk filter is installed. Light through the window of the exposure meter hits the photocell, and under its action, a current is generated in the circuit of the photocell connected to the meter. With an increase in the illumination of the photocell, the current increases, as a result of which the deflection of the meter needle. Shutter speed or aperture is determined using a calculator, which consists of two disks - top and bottom. The upper dial is connected to the ISO setting dial, and the lower one has a ring. On the upper disc there is a scale of diaphragms with designations from 1.4 to 22 and a scale of light sensitivity from 4 to 1000 GOST units (or from 3 to 800 ASA units) and from 6 to 30 DIN degrees. Intermediate marks on the light sensitivity scale correspond to the values ​​11, 22, 45, 90, 180, 350, 700 units of GOST. The lower dial shows the exposure scale for cameras from 1/1000 to 15 s, moreover fractions of seconds are indicated by integers (for example, instead of 1/2 s it says 2, etc.), black numbers on a light background, and seconds as light numbers on a dark background. Also, on this the same disc has a scale of filming frequency from 8 to 64 frames per second with intermediate divisions of 24 and 48 frames per second and