In a conventional silver halide photography system, image information is converted
to chemical signals in photographic film and stored chemically at the same
point where the conversion takes place. Thus, photographic film has the image
storage function as well as the image capture function. Another method of image
capture is to convert the image information to electronic signals. In this case, an
image sensor serves as the conversion device. However, the image sensor used in
the electronic photography system does not serve a storage function as does photographic
film in the silver halide system. This is the most significant point in which
the electronic system differs from the chemical silver halide system (Figure 1.1).