fisheye..thanks for the info....what are some of the most common mistakes made by the new u/w photographer?
Form personal experience, I'd say:
Impatience - taking pictures underwater radically changes the pace of a dive. If you are with a group anxious to keep moving, leave the camera on the boat.
Chasing critters. I still catch myself doing it, mostly because I feel rushed. The result are pics with critters swimming away, which doesn't look very pleasing.
Focusing too much on fish. Especially with a point and shoot that has some shutter delay, trying to take fish portraits can be the most frustrating experience ever. Focus on stationary subjects and look in the nooks and crannies.
Trying to shoot everything there is to see. This is a recipe for distraction and rushing through a dive, pointing the camera at this and that, but not really seeing anything. I found it much more rewarding once I became more selective. On a recent dive, I set a goal for myself, I wanted one good shot of a particular nudibranch. Yes, it was a little hard to ignore a great many of opportunities I came across on that dive, but that way I actually WATCHED the other critters and focused on photography only once I had found a nudi in a good spot. I spent about 10 minutes at that spot, firing away, changing lighting and making other adjustments etc. The very last shot I got before I had to end the dive was the "prize shot". By focusing on one or few subjects you free your mind to appreciate all the other things you will encounter while being ready for good results once you find your "target subject."
Shooting from too far away. Trust me, this is the big one. If you think you're pretty close, you're way too far away. Move in. If you think you're really close, you're still way too far away. Move in. If you think you're about to hit your lens port into the reef, you're probably still too far away but give it a shot. When I was a beginner I used to zoom it as much as I could to avoid having to get so close. Big mistake, because you are not really eliminating the water between your lens and the subject. IMHO, this is THE MOST IMPORTANT rule to keep in mind and the hardest to get used to. Even if you feel overloaded by all the other advice, if you only repeat the "Get closer, get closer" mantra in your head, your shots will improve at least 50 percent.
Putting too much pressure on yourself. Again, I struggled with this one big time, as I live in a landlocked area, and before each trip I drove myself nuts, going "Oh my god, I may not dive that place ever again, I just HAVE to bring back really amazing shots." This is terrible and can take all the fun out of a diving vacation. Make sure you take your camera along, but I suggest you make it your priority to take the experience in with your own eyes instead of viewing underwater life through the viewfinder of your camera. I've done this a lot, and lately I came to realize that while I did get some amazing shots on some of my dives, I don't remember much if anything else of them. On the other hand, the dives where I left my camera on the boat are the ones that really stick in my memory and I remember seeing about 100 percent more critters on those dives.
Hope this helps. Have a great time!!