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.
THINK YOU’VE GOT A HANDLE ON THIS US STATE NICKNAME QUIZ?
Did you ever collect all those state quarters? Put them to good use on this quiz about curious state monikers and the facts around them.
Question 1 of 8
Mississippi’s nickname comes from the magnificent trees that grow there. What is it?
Also called iris.
Origin of iris diaphragm
First recorded in1885–90
Words nearby iris diaphragm
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020
British Dictionary definitions for 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 apertureSometimes shortened to: iris
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