2-5 days
*Light is absorbed as it travels through even short distances underwater, making colors appear dull or monochromatic. To preserve the natural colors of your subject, it's important to stay within arm's reach—no more than 3-4 feet (1m) away.
A flash or constant on light is necessary for close-up, night dives, and deep depths. An external light also brings out more colors in sunny conditions. External lights are typically not used in conjunction with color filters, as the combination will result in tones that are too red or too purple.
The location of the camera's flash in relation to the lens makes it unusable for lighting your subject underwater. However, the camera's flash may be used to trigger an external strobe. Two ports are provided for the connection of up to two fiber optically triggered underwater strobes.
Alternatively, a bright constant-on video light can be used. A constant-on light is not as bright as a strobe flash. Constant-on lights do provide added versatility because they can be used for focus assist and for improved colors when shooting video.