gray card

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.

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

How many repeaters, men inevitable to a life of crime, had come here to be handed a light gray card in The Cage, while other, different men, once-upon-a-timers, had come out carrying the yellow or pink?

From Project Gutenberg