Procedures for Lighting in Underwater Photography. Effect of natural lighting and highlighting colors of subjects creates dramatic contrast in creative compositions. Natural lighting from the sun penetrating the water results in a photographer judging what setting to select to expose enough light to get the desired contrast of the impression. Due to absorption of certain wavelengths of sunlight, a strobe is used to highlight and restore colors that are three to five feet from the flash. Some of the problems is the flash can be to bright and if the camera set on automatic or TTL the background can result in being to dark to achieve proper balance in exposure between subject and background. By adjusting the ISO setting up or down proper balance can occur. Using a test series can result in finding the best settings for your strobe and lens where bracketing of pictures will insure a quality exposure of both. Each strobe will vary in size and setting. To choose which strobe is best, one must understand what is the end result that the photographer wants to create first. Strobe power is measured in Kelvin, (K) temperature that is a temperature measurement system for calibrating the precise color temperature of an illumination source. Different strobes will have different Kelvin temperatures and most have adjustments of levels. If an image of a large subject area which requires greater distance and a higher power or setting will be needed to penetrate the flash to the subject and back to the lens will less lose of color energy waves. The problem is learning to judge the absorption of illumination and what will be reflected. The various colors in subject and surroundings can result in over exposure or underexposure of areas the strobe can not reach. This is a skill self-taught by testing different subjects in different surroundings. It is best to study distance and angle of photographing larger subjects to determine how close can a photographer get to subject and what would be the best settings for achieving the balance in color, background and exposure. Remember to test your different setting before the once in a life time shoot occurs. Plan your strategy for achieving proper lighting and if you can lens, strobe or camera. Test the system first to determine best opium settings and ranges.