Iris Diaphragms, 2.4-41.3 mm Aperture, M4 Thread, 18 Leaves, Pack of 6

The M-ID-1.5 Iris Diaphragm uses 18 leaves for a 2.4 to 41.3 mm aperture range. Designed for smooth adjustment and the best possible aperture shape, each iris consists of an array of curved, spring-steel leaves whose orientation is determined by the relative position of two rings. A pin handle on the inner ring lets you adjust the aperture without risk of obstructing the beam path. M-ID-1.5 Irises mount directly on Posts and Pedestals and have Metric M4 thread. Iris Diaphragms provide continuously variable apertures for applications including setting the numerical aperture of a lens, controlling or measuring the intensity of a diffuse beam, or approximating beam diameters. They may also be used as baffles to reduce spurious reflections and scattered light.