Bracketing for Underwater Photography. Capturing a mood or expression of a fish or a diver ads to the story a picture will express. Trying to achieve the just right photograph of which will display expression, mood, coloration, composition, contrast, lighting, angles, focus and several other skills or techniques requires numerous attempts of exposing frames of film at different settings of the camera, lens and placement of strobe or subject or surroundings. The term of bracketing applies to using a variety of the exposure setting to make sure one photo will be exposed at the prefect setting. When using a manual f-stop camera, changing the f-stops up and down will result in opening and closing the aperture with each change a division of half if increasing the f-stop. When using a camera where f-stop is set at automatic, increase or decreasing the ISO setting by half the speed is like opening the aperture by one f-stop, and increasing the ISO by doubling the setting to decrease the exposure. An example is if using 100 ASA film the setting ISO is 100, decrease to 50 ISO is like opening the aperture. In Marco photography with a Nikonus system with framers, the f-stop is set to the smallest setting to gain the largest depth of field. The strobe is set at six, eight, ten, or twelve inches from the framer depending if a 1:1 or 2:1 or 3:1 framer set is used. By moving the strobe two inches forward or backward is increasing the brightness and changes the exposure. The main consideration is first selecting the correct exposure setting based on available light for the depth of water background, the amount of brightness from the strobe that will be reflected by the subject and what type of background there is which might absorb or reflect the flash. These vary for each subject taken and the science of judging what f-stop to start with is why exposure meters are built into most cameras. The best method is a series of test shots. Use a diver at three feet which holds up a slate painted white. Expose the same subject changing the f-stop from the low to high. Then change to black, then try colors, then change the angle of the shot with white background, blue open water, then towards the sun and then opposite. Each series record on a slate prior to entering the water to make sure nothing is missed. It would be best to use the film you would be using on a real dive. After developing the film look at the differences in all three areas, reflected flash from subject and background. Look closely at facial and hand colors, look at metal from watches and regulator. Notice the difference in background and effect on subject concerning light backgrounds or surface light. Each will change the exposure by increase the f-stop if subject reflects light and decrease if absorbs light. Another consideration is that by taking a series of pictures of the same subject the more likely an image will not catch that fin bent forward, or a tail bent where it doesn't show or the bubbles of a diver in the background surrounds the neck with a silvery shine. Capturing an attention getting expression or displaying a humanly mood on a fish is a result from series of frames of film exposed on the same subject. A good skill development is to take a garbage can, a rubber palm tree and a plastic fish tied with fishing line to a lead weight. Place in the bottom of the pool or in the sand. Next spend twenty minutes photographing at different angles and f-stop settings. This would be like trying to photograph a large sponge, sea fans and French Angle fish. After reviewing your prints what would happen if you only took one or two images of a certain fish you saw on a given dive, the odds of getting a good shot are next to never and an excellent shot is vary rare. Increase your odds by bracketing and changing the angle of exposures. Remember Underwater Photography starts as skill development, then composition followed by technique and finely artistic realization. Email Us Now