Accurate exposure is the essence of good photography.
The Kodak Gray Card is a standard, neutral test target that allows you to minimize variables in correctly determining exposure.
Most in-camera and handheld meters are of the reflection type, and are calibrated to provide exposure information based on an "average" scene, one that contains a balance of light and dark tones equal to middle gray. Exposure errors that can therefore occur when a meter reading is taken off a subject or area that is lighter or darker than middle gray. By taking reflected light meter readings off a Kodak Gray Card rather than a subject of unknown reflectance, more accurate exposures will result.
The Kodak Gray Card is an invaluable aid for standardizing the results in optimal color reproduction and a full tonal range in the final image.
Using the Kodak Gray card
In use, the Gray Card is placed in the same illuminations as the main subject, and angled slightly toward the primary light source. An exposure reading is then taken off the 18% gray surface of the Gray Card. A light meter reading taken off a subject of known reflectance is especially important in critical applications such as copy work and close-up photography.
For Determining Light Ratios
For portraiture, take a reflected-light reading off a Kodak Gray Card rather than the subject for greater accuracy when setting and adjusting light ratios.
For Digital Photography and Video
Use the card's 18% gray surface to determine exposure and as a test target to establish a neutral rendering with digital systems. The 90% white side can be used to adjust white balance on digital and video cameras that offer manual settings.
For Printing
Include a Kodak Gray Card in test shots of critical subjects taken on film or digital media to help you evaluate color balance and density when printing. Because the Gray Card is of known reflectance, you can easily pinpoint exposure time and filtration either visually or with a densitometer or color analyzer. |
