A Murphy’s Law for Exposure

“Never confuse the improbable with the impossible: Burke’s Law.”—Burke’s Law 1963

Back before the Dot Com bust, I wrote for several computer magazines and back then created  a series of  “Farace’s Laws of the Computing Universe.” I figured if Murphy could have a law and Burke (my real inspiration for the idea) then there could be Farace’s Laws as well. When I started writing exclusively about photography, I brought those laws to my writing for Shutterbug and it surfaces in my books as well. I thought it was time to introduce this blog’s readers to the concept:

There’s an old computer adage that goes: “Garbage in, Garbage out” that has been attributed, if not literally, to computer pioneer Charles Babbage. One of Farace’s laws of the Computing Universe is that “The best captured files make the best photographs.” While I don’t always shoot in RAW format, I usually do under tricking lighting conditions. For example, you can’t use any of Adobe Camera Raw’s controls to make up for a helplessly under or overexposed image file. If your digital camera has a Histogram feature use it to home in on exposures while you’re shooting! Or use the camera’s auto bracket control or put the camera in Manual mode and bracket exposures for critically important photographs.

The Exposure slider in Adobe Camera Raw adjusts an image’s brightness or darkness. Moving the slider to the left darkens the image, while moving the slider to the right brightens the image. The values are in increments equivalent to f-stops. A +1.50 adjustment is similar to increasing the aperture 1 1/2 stops. A –1.50 adjustment is like reducing the aperture by 1 1/2 stops.

Tip: Holding the Alt (Windows) or Option (Mac OS) key while moving the Exposure slider give you a preview of where the highlights become completely white with no detail or are clipped. You can adjust the slider until the highlights (not specular highlights) are clipped, and then back off on the adjustment. Black indicates areas that are not clipped, and color indicates areas that are being clipped in only one or two channels.


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.

Author: Joe Farace

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