that travels from the illuminated column to the 
viewed volume. 
It is noted that the brightness required at the 
target and, hence, the flux density in the illumi- 
nating beam are no greater than that required 
for normal camera photography, assuming that 
the line scan system is adjusted to have the same 
sensitivity as the film. Conversely, with some 
sacrifice of resolution, photographs can be taken 
under light conditions insufficient for normal 
camera photography. 
It is realized that the system set forth has 
the shortcoming for deep oceanographic photo- 
graphy, of requiring a large slot-shaped window. 
This can be overcome by utilizing conical scan 
instead of linear scan, This requires a small 
circular-shaped window, whose inner diameter 
may be smaller than its outer diameter. This 
then allows the use of conventional conical deep- 
vehicle windows. Power requirements for the 
camera unit exclusive of illumination would be 
modest. One or two automotive type storage 
batteries would be sufficient for a few hours of 
continuous operation. The system can be 
slowed down for slower line rates in the event 
that telemetering to the surface over low band- 
width cabling is desired. 
278 
