They can be of marginal use...sometimes, on automatic cameras if you turn the flash off it will default to a ___slow___ shutter speed, introducing motion blur/camera shake. With the flash on, these cameras will default to at least 1/60th of a second generally, holding most motion blur to a minimum. The image will be underexposed, but with fast film and the vast exposure latitude of today's C-41 emulsions, acceptable prints can still be made. (whereas if the image was blurry it would be worthless)