NCJ Number
74897
Journal
Security Management Volume: 25 Issue: 1 Dated: (January 1981) Pages: 81-86
Date Published
1981
Length
6 pages
Annotation
Lighting requirements for closed-circuit television (CCTV) are discussed.
Abstract
Despite recent technological advances, CCTV performance still depends on the quality of scene lighting to which a camera is exposed. Although most cameras can produce usable pictures under poor lighting conditions, the best performance in terms of resolution, noise, lag, and shadow reduction will be achieve under good lighting conditions. When a new building is designed or an old one renovated, television lighting requirements for critical areas, such as controlled entrances and cashiering desks, should be taken into consideration. Light source requirements of brightness and color quality are reviewed; and the two pickup tubes most commonly used in surveillance applications, the standard and the silicon target vidicon, are discussed. In addition, the properties of the lens that affect system lighting requirements receive attention: the f-number, which is a measure of a len's light-gathering ability, and the transmission ration, which is the ratio of the light actually passed by a theoretically perfect lens and the light actually passed by the real lens. Finally, the placement of the light source is considered. One of the most important principles discussed is that the light should strike and side of the subject facing the camera. Data graphs and tables and lighting-design diagrams are provided. A reference list is not included.