just as pianists have to practice their scales, I think photographers should practice exposure.
Obtaining correct exposure is critical for maximizing quality and more so for digital capture than for film. The exposure latitude—the ability to over or underexpose a captured image—is greater with color negative film than for any other type of media. Slide film, on the other hand, has the least amount latitude, especially on the overexposure side, which quickly blows out highlight detail. Digital camera sensors respond like a hybrid of those different kinds of color film. In digital capture, there is little latitude for overexposure because any image data is literally wiped out but underexposure has more latitude, almost as much as film. The downside of underexposure is the increase in the amount of noise.
Sometime the best solution is to shoot a series of exposures varying exposures from what would normally be considered underexposure to overexposure. Most cameras offer an automatic bracket option as seen at right on a Pentax digital SLR. In the best of all possible worlds, I start by making an exposure and after evaluating its histogram adjust the camera’s exposure compensation control accordingly. When in doubt, I do what photographers have done since film days—bracket.
Because the LCD preview screen on most digital cameras can sometimes exaggerate an image’s contrast (or even exposure) it’s easy to get what you think is a well-exposed image but what is really slightly underexposed. Only the image’s histogram reveals the truth. Practice your bracketing and gradually you will learn how to evaluate the image on your LCD screen and make exposure adjustments without looking at the histogram.
The top photograph is from my book, “Acapulco, Paradise of the Americas,” co-authored with Don Bain, that’s available on Blurb.com.
Along with photographer Barry Staver, Joe is co-author of Better Available Light Digital Photography that’s now out-of-print but new copies are available at collector (high) prices or used copies for giveaway prices—less than two bucks—from Amazon.