what fraction of the light falling on a piece of photographic film is typically wasted
6.3: Visible-Light Detectors and Instruments Photography represents a huge improvement over the human eye, but it still has limitations. Photographic films are inefficient: only about 1% of the light that actually falls on the film contributes to the chemical change that makes the image; the rest is wasted. Astronomers today have much more efficient electronic detectors to record astronomical images.