IRIS DIAPHRAGM Definition & Meaning

iris diaphragm

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

noun

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 Sometimes shortened toiris

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�y��vlog History and Origins

Origin of iris diaphragm¹

First recorded in 1885–90

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Example Sentences

Examples have not been reviewed.

In the lower power objectives the angular aperture is to be reduced by the iris diaphragm.

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They are also fitted with indicator for registering each exposure as made and iris diaphragm.

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The shutter leaves are formed of segments opening in star shape, giving even illumination over the entire plate the instant the exposure is started, and it has an iris diaphragm.

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Rack the condenser down slightly and cut down the aperture of the iris diaphragm so that the light, although even, is dim.

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Tycho Brahe invented, and applied to the pointers of his instruments, an aperture-sight of variable area, like the iris diaphragm used now in photography.

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