the main difference between a digital camera and a film camera is in a how the image is recorded . a 35 mm camera uses 35 mm film, which must be loaded into the camera and replaced after a certain number of exposures ( images captured on the film . one big advantage to film is that it can be purchased almost everywhere, and it is generally inexpensive . on the other hand, there are usually only 24 exposures on a roll, so the camera must be frequently reloaded. stopping to reload a camera in the middle of an important photographic opportunity - like a wedding or a child's birthday - can be frustrating . you might be missing the best shots while you're opening that next roll of film . moreover, if undeveloped film is accidentally exposed to light - for example, if the camera is dropped and the film falls out - the image will be destroyed