Iris Diaphragm

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iris diaphragm

[′ī·rəs ′dī·ə‚fram]

Iris Diaphragm


a type of stop that is often used in photographic lenses and other instruments to adjust the brightness of the image and to vary the depth of field. It consists of thin, opaque, crescent-shaped vanes that overlap one another, thus forming an approximately circular opening. By moving the stop ring on the lens or a lever connected to it, all the vanes are turned simultaneously, so that the objective’s opening (aperture ratio) is varied smoothly.

References in periodicals archive ?
While this filter revealed many details on the solar disk, the prominences appeared much more conspicuous in the coronagraph and became even more so as the iris diaphragm was adjusted.
Delary Kahn, president of Kahn Medical, inventor and developer of the artificial iris diaphragm implant presented his experience after successfully implanting NewIris in a number of patients solely for cosmetic reasons at the X Keratomileusis Study Group International Congress /Feb.
These new exhibits will be supported by examples of their Kek Universal mills, Kek kibblers, traditional Mucon iris diaphragm and disc valves and Bridge Breaker silo discharge aids.
For food industry contractors and end-user companies alike, the company manufactures a variety of ancillary equipment which includes Mucon iris diaphragm valves, disc valves, Rotalog level indicators and Bridge Breaker discharge aids.
Unlike the photo etching of iris diaphragm delivery systems used by large gas excimer lasers, the LaserSight galvanometric delivery system achieves a photo-polishing of the surface of the cornea.
A newly developed iris diaphragm with 15 aperture blades has been integrated into the ARRI/ZEISS Master Anamorphic lenses to create a bokeh that is perfectly oval and evenly illuminated.