iris diaphragm
- noun
- /ˈaɪrɪs ˈdaɪəfræm/
- Specialized
:
diafragma de iris
- In the microscope, the iris diaphragm allows the user to manage the light intensity for clearer observations.
Examples
-
Abbe condenser with an iris diaphragm and a mechanical stage with a 140 x 135 mm surface area.
Academic text (2002) -
The photographer adjusted the iris diaphragm to control the brightness of the image.
-
To enhance the depth of field, she modified the iris diaphragm on her camera.
Synonyms
15
7.1
A ring of thin plates that opens and closes to control light entering a lens
A part inside a camera that opens or closes to control the amount of light
An adjustable opening in a camera lens that controls how much light enters
How Open
Surface Forms
Morphology
The compound is fully compositional: "iris" denotes an overlapping-plate aperture and "diaphragm" denotes a device that regulates light, so together they describe an adjustable aperture controlling light. Although technical, the meaning follows straightforward composition and has direct parallels across languages, so a B1 learner who knows both constituents should be able to infer the MWE's meaning.
Etymology
Iris diaphragm gets its name from the eye and a ring of thin plates. The iris is the part of the eye that opens and closes to 'let in light', and the diaphragm is a ring of thin plates that fit over each other to make the opening bigger or smaller, so the name describes a device that controls how much light passes through a camera or microscope.