Special film to replace an I’m Back35 focusing screen.
The focusing screen is where the image to be registered by the I’m back35 is formed and therefore it must always be clean. Many times, the shutter itself, because it has dust inside the camera, can deposit small residues that, if not removed, will be recorded in the photograph. To clean this surface, use an air jet and, if necessary, alcohol. Avoid contact with fingers as it may leave an oily stain on the surface.