gray card

American  

noun

Photography.

1. a card of controlled reflectance held near a subject to approximate middle tones and used as a target for an exposure meter.

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Example Sentences

Worse still, he might encounter the insane killer who leaves a triangular gray card inscribed “The Avenger” on the mutilated bodies of his victims.

From Washington Post

Prof. C. G. Abbott of the Smithsonian Institute, in his observations on the sun's eclipse on May 28th, 1900, says in his report: "My experiments showed the corona of the sun was actually cooler than the gray card which had been used at the room temperature."

From Project Gutenberg

The importance of simultaneous contrast is easily demonstrated upon a painting by isolating any colored object from its surroundings by means of a hole in a gray card.

From Project Gutenberg

To every man in uniform I give a white card; to every man without a uniform, who seemed to be there for earnest, I give a gray card.

From Project Gutenberg

There was placed before the subject a gray card, upon which were put a series of two-point distances ranging from 2 to 20 cm.

From Project Gutenberg