Scenes containing large bright areas, such as beach or snow scenes, can challenge both film and digital photographers. On sunny days the range of brightness between the highlights and darkest shadows can be as extreme as it gets, easily over 12 f-stops. The best film and digital sensors can only hold 5 to 7 f-stops of detail. This narrow range of exposure will hold the delicate shades of light-colored hues that appear in the image. This means that proper exposure is important to convey the details that make the scene special.
Determine the Dynamic Range of the Scene
The photographer’s first step is to determine the dynamic range of the bright scene. Use a hand held spot meter or the camera spot meter to measure the brightest area and darkest area in the scene. This will be difficult if you don’t have a spot meter but not impossible. Depending on the scene, it might be possible to walk up to the bright and dark areas to measure them, or you can measure areas near you that can substitute for the broader scene before you. If neither of these options works, you will have to make estimates. The light measurements will tell you how much of the scene will be outside the ability of the film or sensor to record detail. For example, a scene that measures 10 f-stops of dynamic range will have many areas that will be white or black without detail if you were to expose it using an average meter reading.
A critical decision the photographer needs to make is what part of the scene the camera will capture in the 5 f-stop exposure range. This decision determines your interpretation of the scene and how the image will appear to the viewer. Will the image have detail in the highlights and featureless black shadows, or the reverse? Most photographers choose to sacrifice the shadows for detail in the highlights. Letting a few of the smaller, brightest highlights burn out is usually acceptable.
Use the Histogram with Digital Photographs
Digital photographers have the advantage of immediate access to the picture’s histogram for exposure information. The histogram of a wide dynamic range image must touch or be very close to the right-hand side; otherwise the widest range of tones with detail will be reduced. When you let a few of the smaller, brightest highlights burn out, the histogram should show a little cut off on the right hand side (the few brightest highlights) and significantly cut off on the left-hand side (the shadows).
Be aware that there are scenes that are impossible to capture with a single image, since the dynamic range is too large. A sunny scene with Alaska’s snow covered Mount Denali and a foreground of dark green coniferous forest cannot be captured without burning out the mountain or having the forest go black. One solution in this situation is to zoom in on Denali and eliminate the forest in the image and therefore expose the snow correctly. The original scene could only have been made on a cloudy or overcast day with less dynamic range of exposure.
Pictures on the white sand beaches of Florida’s panhandle can present a similar problem. Needing to expose for the overall scene can result in very dark details in shaded areas or people’s faces that are gray (the eye sockets can go very dark) and not very appealing.
Shoot Two Exposures for Maximum Control
One solution in these extreme conditions is to make one image exposed for the highlights and a second image exposed for the shadows. Digital files of these two images can be merged in a graphics program to create a combined image with a wider range of tones showing detail. You will need to use a tripod to ensure that the camera is not moved between the two exposures. Otherwise, you cannot be sure of a perfect merging of the two shots. Also, anything that moves in the scene between the first exposure and the second will not match up, and this will result in a double image of the object that moved.
Shoot in Raw Mode for more Control
Digital photographers have an advantage when they shoot in RAW mode for bright scenes. Carefully adjusting the exposure when processing the RAW file can bring out some of the subtle details in the scene. Photoshop exposure tools can also be used to optimize the contrast and dynamic range of colors to produce the best possible image.
Check your White Balance
Bright scenes, especially those with snow, are even more difficult since another tricky part of the exposure is getting the white balance correct. The white snow picks up color from the light falling on the scene, the sky, and other objects in the scene. Snow scenes usually have bluish shadows and dark areas like trees and rocks. Specific films have unique color balances and can give yellowish snow or greenish shadows that don’t look quite right. Choose film based on personal experience or ask others for advice to avoid problems. The auto white balance setting on digital cameras may not adequately correct for the tints picked up by the snow. What appears white to your eye may not be a true white. Calibrating the digital camera white balance with a known white target will result a better looking snow scene. RAW files give greater flexibility and let you adjust the white balance of the final image.
Careful exposure, shooting digital RAW files, and using Photoshop for final adjustments will let you capture the maximum range of tones in bright scenes. Bright scenes with detailed dark shadows and detailed bright highlights that bracket delicate midtones result in images that delight both the photographer and the viewer.