Lenses for Amateur Motion Picture Equipment (16- and 8-mm)
In all motion picture photography and projection, lenses of high relative aperture must be used. However, on account of the small size of the amateur frame, the focal length is short, and the linear aperture of the lens is therefore small, resulting in considerable depth of field. Thus in cine work, great lens speed is not automatically associated with small depth, as is the case in ordinary photography. — Moreover, as the entire motion picture frame must be seen by the eye at a glance, the angular field covered must be much smaller than in still pictures which may be examined critically and deliberately. This fact is of the greatest assistance to the lens designer because high aperture and field are inevitably somewhat incompatible, and types of lens construction which favor aperture generally cover a relatively small field. — Perspective considerations usually require a projection lens covering only about half the angular field covered by the taking lens, which fact enables projection lenses of very high relative aperture to be made. Some of the types of construction commonly used in amateur cine lenses are described.
- Print ISSN
- 0097-5834
- Published
- 1940-01
- Content type
- Original Research
- DOI
- 10.5594/J00027