Answer :
It is true that an iris diaphragm is a set of overlapping metal plates that expand out to allow more light or fold in on each other to reduce the amount of light.
What is Iris Diaphragm?
Iris Diaphragm is an adjustable diaphragm of thin opaque plates that can change the diameter of a central opening usually to regulate the aperture of a lens. It is an adjustable shutter that allows us to adjust the amount of light passing through the condenser.
To learn more about iris diaphragm, click the given link https://brainly.com/question/13296024
#SPJ4