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(No Longer Available) Digital GrayCapTM

Many gray cards are not well-suited for digital photography. They often are not really neutral, and were designed for use with film as exposure guides, not as a gray balance source. The simple Digital GrayCapTM solves these problems as a sturdy plastic card with a spectrally flat color response.

  • Size: 1x1 inch
  • foam tape included
  • 3 for $20


Questions? Here are answers to Frequently Asked Questions about the Digital Gray Card.

The GrayCapTM card has many advantages:

  • Always have a spectrally neutral source with you. Buy one for every lens.
  • Attaches with foam tape to the outside of your lens cap – It will not get lost.
  • Spectrally uniform - The card maintains its constant gray appearance in a wide variety of lighting conditions.
  • Durable plastic material - Lightweight, strong and can withstand professional and amateur photographers.
  • Waterproof - A gray card you will not be afraid to use in wet weather.
  • Washable - It can be cleaned with soap and cold water to remove fingerprints and grime.
  • Repairable - Small surface scratches can be repaired by the user with a random orbit sander.

Instructions for Use of Gray Caps

The Digital Gray Cap provides you a method of “encoding” the actual color balance of the scene by photographing the card and then processing it in a RAW editor like Adobe Camera RAW. It is processed simply using the White Balance Eye Dropper to click on the Gray Cap within your image. The software will automatically neutralize the area to equal values of red, green and blue, making the gray cap spectrally gray, and therefore your scene neutrally rendered.

The Gray Cap will not work in warm light as it will strip away the warm color of the light by encoding how to make your photograph neutral rather than the warm rendition you would be seeking.

LAB Values of Neutral Gray Sources for Field Work
(a and b values should be as close to zero as possible)

MacBeth Color Checker (or ColorChecker Passport)
white: 96.8 -0.5 1.7
light gray: 81.6 -1.0 -.01
gray: 66.7 -1.1 -0.1
dark gray: 50.6 -0.3 -0.3

SJ Photo Gray Cap
63.6 -0.8 -1.2

WhiBal Card
73.7 -0.3 0.8

Note: The Digital GrayCapTM is designed for digital photography gray balance only. It is not an 18% reflectance card designed for use with light meters to determine exposure. It is also not as light as some prefer, but we have found it works very well with Adobe Camera RAW white balance tool.

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Last updated on March 18, 2015 . Mail comments to: info@sjphoto.com
Photographs and Text Copyright ©2008, Stephen Johnson. All Rights Reserved.