A link budget approach to specifying lights and cameras for underwater applications

Specifying lighting and cameras can be a complex and challenging task for any photographer or videographer. When dealing with the underwater environment the challenges grow exponentially. Anyone who has worked around, on, or under the ocean is well aware that conditions can quickly change dramatically. Visibility, ambient light conditions, and even the power to the equipment in use, can have a significant impact on the quality of underwater images. Acknowledging this variability, however, does not relieve us of the need to specify cameras and lighting systems capable of operating in extreme environments. In this paper we will look at some of the technical aspects of specifying lights and cameras. We start be reviewing some of the - often confusing - nomenclature and concepts. We then look at environmental factors that impact the system performance. Finally, we present a “link budget” model that looks at light output, path losses, and camera sensitivity and noise levels. We conclude with some recommendations on ways to improve the performance of underwater imaging systems.