Nothing shows the reality of a healthy coral reef better than a wide angle photograph of a beautiful hard coral garden. To shoot a coral garden effectively there are a couple of things to keep in mind that will help to achieve the best results:
1. Stay shallow! The best results will be in less than 10 metres of water.
2. Turn off your strobes and use the sun at your back, the sun will illuminate the coral and bring out the colour.
3. Shoot at a slightly downward angle, this will allow you to frame as much of the interesting coral reef as possible.
4. Use a fisheye lens or a higher f-stop (such as f11) in order to avoid bad corners from a rectilinear lens. Bad corners will show very obviously with intricate corals filling the frame.
5. If possible utilize a red filter or magic filter and manual white balance settings. Using a filter will help filter out the blues and greens from the image and create a more even colour tone. Also, shoot in RAW so you can experiment with WB in post processing.
6. If time of day and conditions allow, try to include sunrays at the edges of the photo in order to add a second element in the composition. Including a distant diver or freediver is another excellent choice of a secondary subject.