Underwater Photos & Basics
Underwater photography and videography are the most common diving related activities. There are two types of underwater camera systems to choose from: an amphibious camera - a self-contained waterproof system, and a SLR land camera in an underwater housing.
The difference between taking pictures on land and underwater is the medium you shoot through and the unique properties of that medium. Air is transparent. Water is opaque. Light does not travel in a straight path underwater as it does in air. Water is dense with particles of sand, plankton, and other debris which scatter, reflect, and absorb light.
To achieve clear, colorful pictures, one should learn a few basics
The camera's aperture controls how bright your picture is, with higher numbers making the picture darker and lower numbers brighter. In shallow water there is lots of ambient light and as you go deeper, it will get darker. You will need to adjust your camera's aperture to get a good exposure.
The closer you are to your subject, the less water you shoot through, the fewer particles, the sharper and more colorful your picture. Most beginners shoot from too far. Get as close as the lens allows: as a general rule, three to four feet or closer.
Don't get the blues
Water absorbs the rays of sunlight that comprise color. As you descend in the water column, the warm hues of red, orange, yellow in the color spectrum are gradually lost. Pictures take on a monochromatic blue. To get bright, colorful pictures, you need artificial light.
Water creates optical illusions Objects underwater appear larger and closer than they actually are. This is called apparent distance. Your lens sees apparent distance just as you do. You must learn to judge distance underwater. . The manual packaged with your camera will tell you the minimum focusing distance for your lens.
Blurry pictures are caused by two things: improper focus, and movement when you press the shutter button. First you must learn to estimate the correct distance. To prevent blur from motion, perfect your buoyancy skills so that you can hold yourself steady without kneeling, sitting, holding or in any way touching or damaging the reef. Hold the camera steady with both hands and press down firmly on the shutter button.
Particles in the water reflect the light right back into the lens and the result is a flurry of flecks called backscatter. There are two ways to avoid that: Make sure you are diving in clear water. Be very careful that your fins and gauges don't stir up the sea bed. Use an off-camera strobe so you can position the light beam away from the