Showing results for iris diaphragm. Search instead for genus lithophragma.

iris diaphragm

American

noun

Optics, Photography.

a composite diaphragm with a central aperture readily adjustable for size, used to regulate the amount of light admitted to a lens or optical system.

iris diaphragm British

noun

Sometimes shortened to: iris. an adjustable diaphragm that regulates the amount of light entering an optical instrument, esp a camera. It usually consists of a number of thin metal leaves arranged so that they open out into an approximately circular aperture

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of iris diaphragm

First recorded in 1885–90

Example Sentences

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See Examples For:

iris diaphragm

The shell subunits from adjacent protomers overlap like an iris diaphragm, forming large interfaces in both TcA states.

From Nature ● Apr. 4, 2014

In 1887 Edward Bausch invented the iris diaphragm shutter which made the snapshot camera practical.

From Time Magazine Archive

It is fitted with iris diaphragm and supplied with the Nos.

From Kodaks and Kodak Supplies 1914 by Canadian Kodak Company

The regulation of the cylinder iris diaphragm is accomplished by means of a lever.

From Microscopes and Accessory Apparatus Catalogue No. 40 by Leitz, Ernst

A cylinder iris diaphragm can be furnished in place of the ordinary cylinder diaphragm of Stand II, IIa and IIb at an additional cost of $6.—

From Microscopes and Accessory Apparatus Catalogue No. 40 by Leitz, Ernst

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023