Theoretical and model studies have indicated that placing the light source 10 to 30 ft behind a deep sea camera results in a decrease in backscatter and an increase in useable range. Full scale tests of this technique have been conducted using six light sources with energy capacities of 8,700 Joules each. These tests demonstrate a significant increase in the practical range of underwater cameras. This technique coupled with a large format camera provides a more efficient means of searching the deep ocean floor.
Robert B. Patterson,
"Increased Ranges For Conventional Underwater Cameras", Proc. SPIE 0024, Underwater Photo-Optical Instrumentation Applications III, (1 June 1971); doi: 10.1117/12.953488; https://doi.org/10.1117/12.953488