iris diaphragm

Found in Anh - Anh (Wordnet)

Definition Noun : - A mechanical device used to precisely control the amount of light passing through an opening : An iris diaphragm is a type of adjustable aperture, typically consisting of a set of thin, overlapping metal leaves. These leaves form a central circular opening whose diameter can be increased or decreased, thereby regulating the intensity of light. Usage The term 'iris diaphragm'...