ABSTRACT
The underwater environment is hostile to humans and is seldom suitable for conventional photography, necessitating considerable modifications to cameras and lenses for in-water use. The turbidity of the water and the inevitable concentration of suspended matter induce back-scatter of any illuminant, causing reduction of image contrast. Consequently, the visibility underwater is limited by this and by the strong absorption of light by water, especially of long wavelengths. Practical details of underwater photography have been given by F. Schulke. The increase in underwater photography concerned with exploitation of resources has produced lenses specifically for in-water use with the water in contact with the front element. Special optical viewfinders with frame lines are needed so that the lenses can show the field of view clearly underwater when the viewer is wearing a diver’s mask. Useful results are given in the right circumstances by underwater versions of single-use ‘disposable’ cameras.
