From 525/625 TV Lines to HDTV: The Evolution of Optical Requirements for TV Cameras
Two important requirements make HDTV lenses different from present television lenses. First, the picture is wider, and although the image may be scanned over the same sensor diagonal, the 16:9 aspect ratio makes it necessary to correct distortion better. Second, the quality of HDTV has to be twice as good; the same modulation transfer function (MTF) must be maintained, although the spatial frequency is twice as high. Although this level of performance is not, in fact, new to the optical designer who has already been involved with photography or motion pictures, his task is considerably more difficult because of the following constraints: (1) good camera sensitivity requires high aperture optics; (2) operational requirements dictate long zoom ranges; and (3) a beam-splitting prism is located between the lens and the sensors. This article explores in some detail what is needed and what can be done in order that the lens does not limit the performance of the HDTV system.
- Print ISSN
- 0036-1682
- Published
- 1990-09
- Content type
- Original Research
- DOI
- 10.5594/J02588