A park ranger recently mentioned that he had problems with his camera's automatic exposure. Photography was his passion but he often found that the photos he shot didn't reproduce the beauty he saw. While taking photos using the automatic mode will often be adequate, photos that knock your socks off relies on how well you can expose for the light falling on your subject. In dramatically lit scenes, the camera may not capture the scene as you saw it. The clouds may be washed out in the sky. A person walking on a shadowed sidewalk may be too dark. Most cameras, even point-and-shoot cameras, can be adjusted so the photo you take matches what you saw and produces a photo you'll love.
Auto Exposure 101
When you set your camera on "Auto," the camera takes light readings either from multiple areas of the composed photo, or it exposes for the brightest, closest object. There is a limited amount of contrast that can be captured in a photo. Called "dynamic range," if you expose for the brightest highlights, some areas can go black and lose details in the shadows ("shadow detail"). Conversely, if you expose for the dark areas, white areas may become gray and muddy.
Exposure Compensation Adjustments
Exposure Compensation is a relatively fast way to change the exposure. Photography that is dramatic may require adjustments to get the picture you want. To begin, you must bravely change your camera setting away from Auto to the "P" (program) mode. Don't worry, your camera will still make most settings automatically. However, in the P mode, you are able to adjust the exposure, turn off the flash, and tweak a few more controls.
Many cameras have an exposure compensation button. This is the button with a plus triangle and minus triangle that make up a square. Press the button to bring up the EV (exposure value) slider. If the shadows have gone black or are too dark, lighten them by sliding to the + side. If the photo looks too washed out and white, move the slider to the minus side.
Typically, you will choose to use exposure compensation after you shot a photo and looked at it on your camera. That is the beauty of digital photography. You can delete the photo and take a few more shots adding or subtracting exposure. Few cameras will let you see your adjustments while you shoot the picture so you'll need to review each shot until you get what you want.
HDR
A camera's limited dynamic range of contrast means that dramatic lighting can be difficult to reproduce. If you expose for the plants, the sky is washed-out and vice versa. Exposure compensation may help, but you still won't achieve the best of highlights and shadows.
HDR ("high dynamic range") is becoming available on more cameras. When enabled, the camera shoots three photos in rapid succession. The first is underexposed, then normal exposure, then overexposed. The camera combines the three photos into one shot. HDR can have stunning results where there is brightened detail in the shadows bringing up the leaves of plants while the darkened sky has great clouds. HDR is best used with stationary objects and landscapes as anything moving in the photo composition will be blurred when the photos are combined. A great use for HDR is when shooting indoors where you want to also expose for the scenery through a window.
Auto Bracketing
Auto Bracketing works similarly to HDR. When enabled, the camera takes three photos with different exposures. One exposure will be the normal exposure, another will be underexposed, and the third is overexposed. It differs from HDR because the camera is shooting three separate photos. Choose the photo you like best.
Another difference between auto bracketing and HDR is that auto bracketing allows you to set how much you want to underexpose and overexpose. Choose up to two stops of exposure difference. Each stop lets in twice as much, or half as much, light. Auto bracketing gives you a better chance at getting the shot you want without thinking about it each time you take a photo. Still, you will have to go through three times the number of pictures and get rid of those you don't like. It is best to use auto bracketing when you are out taking a lot of photos of nature or other beauty shots, or when the photos you take are not turning out the way you like.
Point-and-shoot cameras and some DSLRs include a number of Scene modes to handle difficult lighting situations. Beach, Snow, candlelight, night landscapes, and backlit people or objects are a few scenes that can be used to be sure you are getting the right exposure.
Do you ever take your camera out of Auto mode?
