Digital Photography - Real Life Experience - Shooting Wide Angle - Page 14

Real Life Experience - Shooting Wide Angle - Page 14

Scoto's Reef - Bahamas
On a trip to the Bahamas on the Nekton Rorqual I shot my Nikon D100 with a Nikon 12-24mm f4 lens. The following text will describe my shooting procedures. I shot in the manual mode. Before entering the water, I changed the metering mode of my camera to spot meter. I would use the meter to determine the exposure that I needed for the available light portion of my picture.
Lighting Conditions - Available Light and Strobe When you are shooting wide angle photographs, there are two exposures that you must be aware of. The first is the available light exposure. This is the amount of light that is falling on your subject. In the bright, clear waters of the tropics, this exposure often happens by mistake. At a depth of 60' on a sunny day with an ISO sensitivity of 200, the available light exposure could be around f11. If you are shooting 2' away from your subject with an Ikelite 200 strobe on half power, your flash exposure would be f11. By setting your exposure for the flash distance at f11, you match the available light exposure and don't even realize it. In the photo above, I metered the midwater and found that I needed a lens opening of f10 with a shutter speed of 1/125th of a second. I set my Ikelite 200 strobe at 1/4 power. The lens opening and shutter speed setting gave me the blue water background color and the flash gave me the color in the sponge and reef. Okay, how do you go about determining the correct exposure. First, remember that the available light exposure is very important in wide angle photography. If you are shooting photos of shipwrecks, it becomes even more important because if you try to capture a large area of a shipwreck, the available light exposure will be responsible for all the lighting. Your strobe is useless if you are more than five feet from your subject.
In the picture on the right, I pointed my camera up towards the midwater and metered where the spot is shown. I zeroed the meter using the shutter speed and the lens opening. My initial reading was f13 at 1/100th of a second. The Internal Display on the D100 Once I had my exposure for available light, I determined how far I was from the sponge on the reef (approximately 2') and I set my Ikelite 200 strobe to 1/2 power. I took the shot and then looked at the histogram. This is what I saw. This histogram shows the image as underexposed. I took another photo and opened up the lens opening to f10 and left the shutter speed at 1/ 100th of a second. The result is the photo at the right.
In the photo on the right, I metered the midwater where the yellow dot is. This gave me a lens opening and shutter speed of f8 at 1/125th of a second. The reason for the larger sized f-stop was that I was pointing the camera more horizontally. As you point your camera towards the surface, the bright surface water dictates a smaller lens opening. The shots that you see here were all taken on the same dive at the same time of the day. In the shot above this one, I was pointing the camera at an upwards angle so I needed a smaller lens opening. To compensate for the larger lens opening on this shot, I had to turn down the power on my strobe. I changed my strobe power from 1/2 power to 1/4 power and took the shot. I was very pleased with the results.
This was a more difficult shot because I was under the boat and the diver and boat were far enough away that the strobe was not going to help the photo. I turned off the strobe and metered the midwater where the yellow spot is. You want to make sure that you stay away from the sun when metering. It will give you a reading that will seriously underexpose the image. As it is, to get a good exposure of the majority of the photo, I blew out the highlight area where the sun is. The exposure on this photo based on the meter information was f8 at 1/125th of a second.

To take this photo, I again turned off my strobe as the divers were too far away for the strobe. I metered where the yellow dot is and used an exposure of f5.6 at 1/160th of a second. If I was still using a shutter speed of 1/125th of a second, my lens opening would probably been f8. Again, the large lens opening and the contrast range from light to dark blew out the highlights. I still like the photo. Next - Fixing Overexposed Jpegs