by Rolando Gomez
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In photography, outdoor light is ideal when placing subjects in “open shade” or covered areas with directional or reflected light as the main source. The problem for most photographers is proper exposure of the scene and subject. This happens often, and unless a photographer invests in an incident, hand-held light meter, they probably will have inconstant exposures.
So how does a photographer achieve the correct exposure in existing light, reflected or not? Relying on a their fancy meters built into their camera, especially in awkward lighting conditions, is not the answer unless you combine it with an 18% gray card .
Most photographers underestimate reflected light which affects camera meters. A camera meter tries to “average” the intensity of light barrelling through the lens—a camera meter doesn’t take the subject into account, it averages the scene. A more expensive camera with a spot meter is preferred, but it too bases the exposure reading on tonal range and not necessarily 18% gray.
A camera meter is calibrated to a "benchmark" average scene or "benchmark" average skin tone. This calibration is compared to the scene during the meter evaluation process. Not all scenes or skin-tones are benchmark. Cultural differences in our skin tones are not taken in account in camera meters, neither is snow or beach scenes.
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Gray Card |
How does a photographer obtain the correct meter reading, or exposure reading, relative to the 18% gray tones for both black and white, and color film tonal ranges to reproduce the most accurate tones? Simple, just purchase an 18% gray card.
The highly accurate gray card is easy to use, and less expesnive than buying a hand-held, incident light meter. For photographers that own a hand-held meter, chances are they purchased it because of its ability to measure studio flash and on camera flash. That’s fine. Save it for the studio or location shooting with strobes, it’s too expensive to lose or damage, and there is no need to carry a hand-held meter in your camera bag all the time.
An 18% gray card, is real simple to use. Simply have the subject hold the card, with hands behind the card, pointed toward the camera. Tilting the card in the same direction of the source of light that will hit the subject is acceptable.
The photographer then tightly frames the card in the camera viewfinder where only the card can be seen. At that point, the camera meter reading is noted. This reading can be used in the same general area and lighting conditions for shooting the subject.
The camera light meter may change, but ignore it. The gray card reading is a true reading, while the camera meter can be “fooled” from the scene, or back and foreground around the subject. All the tones, from highlights to shadows should reproduce accurately in a scene when a photographer uses this method—and skin tones should be accurate too.
Bear in mind, while tones will be accurately represented, film characteristics can affect the tonal quality, and in color, the color interpretation of the color spectrum. As an example, Kodak E100SW will produce more saturated warm tones, while E100S will produced less warm, but saturated tones. Knowing film characteristics will help “fine-tune” a photographer's meter readings, but most of all, using an 18% gray card will match a film’s capability to reproduce 18% gray tones, which all films are optimized for when reproducing images that involve traditional photography with subjects and scenes.
Order your 18% gray card here--it comes with instructions in four different languages, English, French, German, & Spanish,
©2002 Rolando Gomez
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