They make this:
Underwater Photo Simulator for iPad
The Underwater Photo Simulator allows you to practice adjusting f-stop, shutter speed and flash power settings for wide-angle, close-up and macro underwater photos. For each of the 3 distinct types of UW photography, the program contains a matrix of images made of a real UW wide-angle, close-up or macro scene at a typical range of apertures, shutter speeds and flash power settings. The wide-angle and close-up sets have an f-Stop range from f-2.8 to f-11.0. The macro set has an f-Stop range from f-5.6 to f-22. All sets have a shutter speed range from 1/15 sec. to 1/125 sec. and flash power settings from Full Power to 1/16 power. To switch between sets, just touch the icon in the tab bar at the bottom of the screen to select which of the three sets you wish to use. You can change any of the settings and see what the result looks like.

An underwater wide-angle photo has two unique exposure problems to solve. The exposure of the main subject in the foreground is controlled by the combination of f-stop and flash power. Shutter speed is not a major factor for the foreground subject. The background, however, is controlled by the combination of f-stop and shutter speed. The limited reach of the flash has relatively little effect on your background exposure. The key to a good underwater wide-angle photo is to get the foreground and background exposures to balance and look as natural as possible. UW close-up and macro depends more on the flash for proper exposure and the simulator will show you that effect too. The UW Photo Simulator will allow you to experiment with the settings and see the results in a real world situation. As you change any setting, the results are reflected in the UW scene displayed.

The Randomize function will scramble the settings so that you can practice making corrections to achieve a good exposure.

Welcome to This site is designed to present support materials and links for Steve Fish's books, apps and instructional materials. Here you will find news on availability of new titles as well as links to other sites of interest to Underwater Imaging enthusiasts. For a look at Steve's UW photos, videos, free tutorials and downloads visit his main website at