iris diaphragm

i·ris di·a·phragm

I i

Definitions of iris diaphragm words

noun iris diaphragm 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. 1
noun iris diaphragm 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 0
noun iris diaphragm a device consisting of thin, overlapping metal blades that can be adjusted to form an aperture of varying size for camera lenses, etc. 0
noun iris diaphragm An adjustable diaphragm by which the diameter of an approximately circular opening may be controlled, as for regulating the aperture of a lens; it consists of a number of movable thin curved plates fastened at regular intervals around the inside of a ring, the positions of which are simultaneously adjusted by a single knob on the outside of the lens. It is used in cameras and microscopes. 0

before 1885

One of the 21% newest English words

First recorded in 1885-90

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exclamation

This term is known only to a narrow circle of people with rare knowledge. Only 5% of English native speakers know the meaning of this word.

According to our data most of word are more popular. This word is almost not used. It has a much more popular synonym.

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