Iris Diaphragm
The iris diaphragm in the optics carrier of your
M series microscope has the same purpose as
those in a camera shutter: it regulates the avail-
able light, which changes the depth of field. The
"depth of field" (or "depth of focus") is the area
of a specimen that is brought into sharp focus.
Leica M series
Closing the iris diaphragm
Close the iris diaphragm by turning the
★
knob to the left. The subject appears darker
and the depth of field increases.
User Manual
Opening the Iris Diaphragm
Open the iris diaphragm by turning the
★
knob to the right. The subject now appears
brighter, but the depth of field decreases.
38