To understand this topic better one has to know barrel distortion and what causes it. It is a condition which causes images to appear spherical and inflated which is as a result of lens effect.
The effect is associated with angles that are wide and they occur at zoom lens near the wide ends. This effect is amplified by converters. The condition is manifested in images where there are straight lines and more specifically when they near the edge of image frame. Underwater Photography – What is Barrel Distortion has been elaborated in details below.
Barrel distortion causes image magnification to decrease as the distance increases from optical axis. The visible result will be an image mapped in the region of a sphere. Deformation in an image can come about due to lens characteristic or camera position from the object.
If it is your first time to take photos underwater, the following tips will help you. If you are three to four feet you will have to put the camera flash on, the flash type should be forced and not auto. Then change your camera to macro mode depending on distance you are from the object.
If you come two to three feet to your object, turn on internal flash, and use auto white mode when your internal flash is on. It is advisable to have your camera magnified because this affects your focus, and you do not have to move closer to the subject. Move closer to the subject and get low but still on eye level. Take photos especially when the subject is looking or facing your side.
When you want to take photos with your camera flash off, by utilizing ambient light, and still want to have quality color, one has to switch the camera into underwater mode or put into use white balance manually. If your flash is on and you still take a shot of a subject three feet away, your image may show some back scatter, except if you are in very clear waters.
Always keep in mind the closer you move to the subject the better contrast you get and improved color quality with better sharpness. Use a light or flash diffuser to soften your light.
You can lock focus if you are having hard time focusing on your subject and having a clear shot due to time lag by pushing halfway your shutter button and holding still your camera. This is mostly used for constant subjects.
When you want to improve your photo quality purchase an exterior strobe, but one must know the art of controlling the aperture of their camera and how to use strobe. It is advisable to take practice shots by setting your camera indoors first.
Some of the equipments needed for this operation include compact camera, lenses which are the key for good photos, two perfect strobes, get an underwater housing, oxygen, ports and camera body. Keeping in mind you have to protect the equipment you are using. To take this as a career profession one has to be a good diver to be able to stay underwater for quick sometime to take their required photos.