The farther the object will be located, the angle B is greater, hence the largest angle B can determine the distance to the object. The advantages of rangefinder cameras – less camera shake when shooting through a lack of mechanism for lifting the mirror, not the so-called camera shake. Reduction in time from clicking the shutter to open the gate. The main disadvantage is the difficulty of working with long lenses, as the distance measuring accuracy is reduced, and for this purpose are used interchangeable viewfinders. Types of closures. Photographic shutter – the mechanism that opens the rays of light, passing through the object, access to film, plate or on a photosensitive surface of the matrix digital camera and after a precisely determined period of time stopping him.
With the help of the gate performed short excerpts, hundredths, thousandths of a second. The gates are divided into central and curtain. Central shutter, it part consists of several metal blades placed between lenses, lens opens and closes in the center of the current openings. The entire surface of the photosensitive area is illuminated simultaneously. Curtain shutter, got its name from its stand in smb. 'S light detail – lightproof blinds, which consists of two parts, separated by a transverse slit. The lower limit of excerpts from the shutter curtain is 5 times smaller than that of the central gate. The shutter is the most difficult part of the camera, so that the principle of the gate, its main characteristics is necessary to know all the photographers.