BS 4793:1972

Covers zoom lenses, variable focal length lenses and single focal length lenses, used in either black-and-white or colour reproduction systems. These recommendations adopt the optical transfer function (OTF), or more specifically its modulus, the modulation transfer function (MTF), as the method of assessment and specification of image quality. Covers the performance of lenses as a complete optical unit but does not deal with the performance of individual component parts.

These recommendations are for the specification and assessment of the optical performance of lenses for use with television cameras. These may be either zoom lenses, variable focal length lenses, or single focal length lenses, and they may be required to operate in either black-and-white or colour reproduction systems.

A special feature of these recommendations is that they adopt the optical transfer function (OTF), or more specifically its modulus, the modulation transfer function (MTF), as a method of assessing and specifying image quality.

These recommendations cover the performance of the lens as a complete optical unit but do not deal with the performance of individual component parts. The condition of test must however include any additional glass paths between the lens and the image plane that are required by the optical design, such as may be introduced by colour filters, beam splitting blocks, the face plate of the camera tube, etc.