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 shown at the top of the screen.