The biggest obstacle to good underwater photography is, oddly, the water. Water absorbs light and steals the color and clarity from your photo. Use a wide angle lens to get closer to your subject and get some of that water out of your underwater photos.
A wide angle lens is absolutely essential for shooting the big stuff like wrecks and whale sharks. Fit more of your subject into the frame for a photo with the same impact as the real thing!
It seems counterintuitive, but a wide angle lens can also make your macro shots pop. In many situations, the addition of an external wide angle lens can both improve the sharpness of your macro photo and expand the backdrop for more dramatic composition.
The Ikelite W-20 is a completely waterproof unit and can be removed and replaced while underwater for maximum versatility. Available with either 46mm or 67mm threads for easy attachment to almost any digital still or video housing. To check compatibility with Ikelite housings, please refer to the housing instruction manual or webpage.