Here are a few tips to help out those new to the digital UW photo realm.
1. Remember that photography is all lighting and background. Relative distance to your target/subject also will play a factor in the quality of any shot.
2. Digital cameras generally have manufacturer settings that are never correct for any environment of UW photography.
3. There should be a manual hue/white setting on a digital camera. You will need this setting to fine tune your camera to the particular dive conditions you will be shooting in.
4. Light is everything, but it can be your worst enemy. External strobes are the preferred lighting element, not the onboard flash of the camera. Be careful though, in low vis conditions (similar to what you find in a lake), you will get a lot of backscatter from ANY lighting device if your hue is not manually adjusted for the equipment and conditions. That backscatter will generally illuminate any silt in the water near your target of choice, thus ruining your photo op.
5. A slate IS your best friend. Use a cleaned slate to fine tune your hue settings while in the water. It will take a few practice shots to get the settings near satisfactory. To do this, you need to enter the manual hue mode of your particular camera, then take a picture of your slate at about 3+ feet from you, view the shot, then adjust as necessary and repeat until you are satisfied.
6. Stay as still and stable as possible when shooting. Hovering IS NOT a preferred method of shooting as it disrupts the stability of the camera, so practice practice practice.
7. Housings are bouyant. If you do not have weights to compensate for this or you are new to UW photography, you may find difficulty with UW shooting until you get used to the bouyancy of the equipment.
8. Neck straps are a big NO NO! A wrist strap or D ring w/ lanyard should be preferred method of retention. Please be sure there is a quick release buckle on the strap to allow for emergency removal if it is ever needed. I incorporate a kydex buckle similar to what is found on fins.
9. Learn to maintain your equipment. This is absolutely vital as it can be the life or death of your electronics. Keep in mind, if you experience a flooded camera housing, discontinue the dive with that piece of gear. In an ocean environment, it is possible that a nearby shark may key from any power leakage into salt water as it creates an interesting electric signal that can attract a shark. Have extra O rings on hand (can you say save-a-dive kit?).
10. Those dry-absorb packets you find in factory packaged electronics are a good thing to have in your housing. One is all it takes.
11. Most importantly, share your photos and lessons learned with others. Every camera is different and as technology develops, the methods of UW photography may change a little. Others may have tips on a particular piece of equipment for you.
The pics in my profile illustrate the difference in lighting and manual hue settings. Granted the helicopter, moped, and piper were at 25-40ft, natural light, and murky (lake was turning), but the hue settings were automatic and not manual; the shot with the student is with minor hue adjustments, 15ft depth, and natural light.