Proper Exposure & ‘The Sunny 16’ Rule

“So the darkness shall be the light, and the stillness the dancing.”—T. S. Eliot

If you agree that lighting is one of the key elements that differentiate a good photograph from a snapshot, then it’s necessary to understand proper exposure. Believe it or not, there was a time when cameras did not have built in light meters, let alone automatic exposure. In those days, photographers either used a hand-held exposure meter or relied on the data sheet that was packaged with each roll of film, providing basic exposure guidelines for taking photographs in bright sun, hazy sun, or cloudy conditions.

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The other widely used exposure method was based on the film’s ISO rating and the aperture f/16 aka the “Sunny 16” rule that is just as valid today as it was back then. Here’s how it works: To take a photograph in bright sunlight, the camera’s aperture was set to f/16 and the shutter speed is whatever comes closest to the ISO number. For instance, if you were using ISO 125, a sunlight exposure would be 1/125th of a second at f/16. The correct exposure for ISO 400 would be 1/400th of a second at f/16 but since most cameras don’t have a 1/400th shutter speed, the closest speed of 1/500th was used.

The ability to tweak the exposure, even with today’s sophisticated cameras, can make or break your image quality and content. I’m always surprised at the number of people who don’t care about correct exposure, saying, “I’ll fix it later in Photoshop.” When exposure is concerned there’s only a partial truth to this statement. Adobe Photoshop can become a crutch for sloppy camera work but you still need to be careful in the arena of proper exposure. A digital image that’s too far over or underexposed cannot be completely saved with image editing software. Please re-read the last sentence.

You can make minor adjustments to the automatic exposure settings while shooting, including using the any of the different metering patterns available within the camera and maybe even pull out a hand-held meter from time to time. My favorite tool for tweaking exposure is exposure compensation. No matter what camera mode, you can shift exposure to satisfy your creative needs to slightly over or underexpose the image using the camera’s exposure compensation control. I hate to be the one to break it to you you’re going to have to read your camera’s manual to find out how your camera accomplishes this function. And take a look at the Histogram from time to time. It’s not a perfect way to determine exposure but it’ll get you in the ballpark.

There are as many ways of achieving a “proper exposure” as there are camera models so give one of these methods a try the next time you’re out shooting. Don’t just accept the camera’s automatic exposure (and then complain about it later) use exposure compensation to make it more than just another snapshot.

light.bookAlong 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.

 

Author: Joe Farace

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