You'll need to attach blue 'excitation' filters on your strobe(s), or use very bright UV or deep blue lights, to stimulate fluorescence removing green, yellow, and red wavelengths of white/visible light. (Note: blue light is believed to be more effective than UV light in exciting the fluorescent photoproteins, and therefore better for photography). A yellow 'barrier' filter on your camera lens or housing's port then blocks the excitation blue light, allowing green, yellow, orange, and red fluorescence to be recorded onto the camera's sensor. A yellow mask filter will allow you to see much more fluorescence than without one while scanning the reef with a blue spotting/focus light, but may not be needed on your mask when you're actually shooting. You'll need a bright blue focus light (such as the Nightsea Light & Motion SOLA, or Dryon Solaris UV lights), enabling you to focus on your subject at night, with a darker yellow filter on your lens/port, it can be very difficult to see your subject clearly through the viewfinder and focus. Don't use a white focus light unless it's triggered to turn off instantly as you take a shot, as this will ruin your image. Special blue lights such as the Nightsea Light & Motion SOLA have different power settings which is useful, and can also have an attached phosphor filter to quickly convert it to normal white light for use as a primary dive light when needed. These special lights can be expensive though, so a cheaper option is to use a blue filter on a normal, powerful dive light.
