Tuesday, August 14, 2012
Proper Exposure Matters!
Translating the film-based Zone System to a digital way of shooting and seeing
|This Article Features Photo Zoom|
Sounds easy, doesn't it? In Adams' world of film, this meant understanding and controlling the relationship that real-world exposure values have with the reflective tones one hopes to achieve in a print. Adams also used various techniques in his "subsequent treatment" (read: film processing), allowing him to expand or compress the tones within that scale to complement his subject matter.
When identifying the tones that might be produced by a 10 ƒ-stop range in his Zone System, Adams came remarkably close to shades of gray as they occur in a gamma 2.2 space, using 10% increments in Lightroom's 0 to 100% scale (Fig. 4).
Just as it did in the Zone System, exposure comes first in any digital test. An optimal digital exposure places a value that you want to be pure white as high as possible in your exposure range. Adams called this bright value just above Zone IX "the maximum white value of the paper surface."
For the purposes of these tests, I'm adjusting my exposure to place my starting value at the highest measurable tone (99.8% to 99.9%) in the gradient that isn't clipping (100%). Of course, the clipping point that each RAW processor indicates will be different, but once you've made a commitment to a specific exposure, the rest of your tones flow from that.
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