optical center

American  

noun

Printing.

1. a point about ten percent above the exact center of a printed page or layout.

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Example Sentences

Scientists believe high-energy cosmic rays impacting on the eye's retina or the brain's optical center cause the flashes.

From Time Magazine Archive

It is assumed that the photographer knows exactly what the focus of his lens is, and that he is able to measure accurately from its optical center.

From Bromide Printing and Enlarging A Practical Guide to the Making of Bromide Prints by Contact and Bromide Enlarging by Daylight and Artificial Light, With the Toning of Bromide Prints and Enlargements by Tennant, John A.

Upon placing the guillotine shutter in the optical center of the objective, what will occur?

From Scientific American Supplement, No. 430, March 29, 1884 by Various

Yes; it is easy to understand that for the same time of exposure, and consequently for the same result, the aperture may be so much the smaller in proportion as the optical center is approached.

From Scientific American Supplement, No. 430, March 29, 1884 by Various

The ratio of the apertures that give the same results at the optical center or behind the objective is as that of the diaphragm employed to that of the back lens.

From Scientific American Supplement, No. 430, March 29, 1884 by Various