|
|
Angle of View vs Angle of CoverageThe angle of view of a camera lens is the amount of the subject area that is seen and reproduced on film. It is determined by the lens focal length in direct relation to the film's format. There are three angles of view for each film format: horizontal, vertical, and diagonal, with figures calculated with the lens focused at infinity. Horizontal is the standard reference. Angle of coverage, on the other hand, can be defined as the angle formed by the entire image circle projected onto the film by the lens. Angle of coverage is directly determined by lens design, not focal length. It must be noted that the angle of coverage is affected by the f-stop of the lens and should be referenced at a given f-stop, or aperture number. The angle of coverage is usually given @ f/22 with the lens focused at infinity. Check manufacturers' specifications to be certain. Angle of coverage is an extremely important specification to examine when choosing a large format lens. Comparing the angle of coverage between lenses determines which lens will allow the greater range of camera movements – the greater the angle of coverage, the greater the amount of view camera movements. In summary, angle of view must be given for a specified film format, and is dependent on lens focal length. Angle of coverage is the complete image forming angle of a lens and is determined by the lens design. |
