Application for exposure settings on the camera. A good helper when shooting on film. First you need to set the ISO and point the phone at the subject. When setting the shutter-aperture pair on the camera, you should focus on the ruler at the bottom of the screen. In the first row - the number of aperture, in the second - the shutter speed corresponding to the current exposure. The ruler can be moved horizontally. It can be used in exposure meter mode (light meter). The exposure value (EV) is