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Basic design improvements over the pinhole camera include:

(1) a means of aiming the camera that will also allow image composition (a viewing system);
(2) a light-bending optical device fitted into the hole to focus light from subjects at various distances onto the film’s surface (a lens);
(3) a mechanism to move the lens closer to or further from the film so the lens can sharply focus near or far subjects onto the film (focusing control);
(4) a mechanical device that adjusts the size of the hole (called the aperture ) so more or less light can pass through it (aperture-controlling diaphragm);
(5) a light-blocking gate that can be opened to let light reach the film for a predetermined and very precise time and then shut to keep light away from the film (a shutter); and
(6) a film-changing mechanism that enables several pictures to be taken in succession (film advance system).