equivalent focal length

British  

noun

1. optics the ratio of the size of an image of a small distant object near the optical axis to the angular distance of the object in radians

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Example Sentences

See Examples For:

equivalent focal length

The telephoto camera remains exclusive to the 13 Pro phones, and Apple has increased its equivalent focal length to 77mm, or three times longer than the primary camera.

From The Verge ● Sep. 15, 2021

It starts with a gigantic 1/1.7-inch Exmor RS 12-megapixel sensor set behind a Zeiss lens at a 24mm equivalent focal length.

From The Verge ● Jul. 13, 2020

Yerkes Observatory 23·5 7·7 Ritchey, 1901 Ritchey, Cassegrain, with an equivalent focal length of 38 feet.

From A Popular History of Astronomy During the Nineteenth Century Fourth Edition by Clerke, Agnes M. (Agnes Mary)

For many months most of the observations and photographs have been made with the Cassegrain combination of mirrors, giving an equivalent focal length of 134 feet and involving three reflections of light.

From Astronomy: The Science of the Heavenly Bodies by Todd, David Peck

Even when attached to a telescope giving an equivalent focal length of nearly 150 feet, the camera only gives a very tiny image of the planet.

From To Mars via The Moon An Astronomical Story by Wicks, Mark