Some Technical Aspects of Underwater Cinematography

The flat-port camera housings sometimes used by scuba-diving cinematographers are subject to coma, astigmatism, pincushion distortion and chromatic aberration as well as a magnification effect that makes objects appear 33% larger than they really are. To correct these effects, concentric or “dome” ports of Plexiglas are now available in housings for the 16mm and 35mm Arriflexes, the 16mm Beaulieu and the 16mm Kodak K-100. Shooting through water reduces the apparent object distance by 25% (or even more with a dome-port), so plus-diopter lenses or extension shims are used as in close-up photography. Other correctors include a reversed Galilean telescope called the Ivanoff corrector, the Cousteau dome with its negative meniscus and — the best choice — the water-contact lens that is intended to be used only in water. Optical viewfinders are now replacing the wire-type finders. Tungsten floodlights should be used for side-lighting or top-lighting, but if batteries are used they should have catalytic protection against hydrogen explosions. The author prefers Ektachrome MS film 7256 and Ektachrome EF film 7241 for normal and low-light conditions, respectively.

Print ISSN

0361-4573

Published

1973-12

Content type

Original Research

DOI

10.5594/J07633