Location Lighting for Television

4

Television Optics

An understanding of basic optics in relation to television is important in coping effectively with the needs of lighting on location. The basic television optical parameters are:

Focal length f-no. angle of view depth of field

4.1   Focal Length

The focal length of a lens indicates the ‘bending’ power of a lens, and it is usually quoted in mm. Figure 4.1 illustrates the bending of light rays to a focal point, due to the refraction of light through glass. A short focal length lens has a greater curvature in its surfaces and bends the light rays significantly. This results in a wide angle of view of the scene (Figure 4.1). A long focal length lens produces less bending of the light rays (shallower curvature of the lens surface) ...