| abstract |
An underwater visual recording system capable of making consistently in-focus visual records of submarine objects includes a camera having a lens system with a predetermined depth-of-field, a first laser structured to emit a beam of coherent light of a first wavelength range, e.g. green light, a second laser structured to emit a beam of coherent light of a second wavelength range different from the first wavelength range, e.g. red light, and a support that holds the first laser spaced apart from the second laser with the camera therebetween so that the two laser beams project forward of the camera and cross one another within the camera's depth of field. In use of the system, it is positioned so the point of crossing of the laser beams is on the submarine object and then the camera is operated to make a visual recording. |