Fluorescence emitted from Tube Worm (Dodecaceria sp) and Encrusting Coralline Seaweed, Papua New Guinea - stock photo

Fluorescence is the process in which electromagnetic radiation (light) of one wavelength (color) is absorbed and light of another wavelength is emitted. Most of us have seen this on land with ultraviolet (or black) light. While fluorescence diving started with ultraviolet light, most fluorescence diving is now done with blue light. The process of fluorescence creates its own special requirements for photographers. The glow can appear very bright when you are looking at it in the dark, but that is because our own eyes are such good sensors. The process of absorbing and re-emitting light is actually quite inefficient, and there is a lot less light coming back toward the camera than you are used to for conventional white-light imaging. It may seem obvious, but the best subjects for this type of photography are the ones that appear to fluoresce the most. Some marine animals fluoresce brighter than others, which will make photographing them much easier.