ABSTRACT
The lighting of a subject for photographic or television purposes, as distinct from illuminating it, has several major functions – other than special lighting systems or devices for specialist applications. For many technical illustration purposes, shadowless lighting is required. Photography makes use of various artifical sources of light for illumination, primarily incandescent or discharge sources and chemical or electronic flash sources. A problem with integral flash units or those attached to the camera is that of red eye where the proximity of the source to the optical axis of the lens allows light to be reflected from the retina of the eye of the subject. A luminaire design termed a spotlight uses an optical system designed to produce highly directional lighting over a small solid angle to give an approximately collimated beam. The lighting of a small subject may be difficult in that available lighting units are comparatively large and not easily manoeuvred into suitable positions.
