Convert NA to angle

Iris diaphragms provide adjustable aperture range from zero aperture up to Ø120 mm. These continuously variable diaphragms are available with blades from springsteel, stainless steel or alloy for different optical applications and operating temperatures.

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Numerical aperture of lens

Iris diaphragms provide a continuously variable field stop for controlling the focal length of an optical system or for adjusting the diameter of a beam. Iris diaphragms enable smooth operation over the lever travel, from maximum to minimum aperture. Lever actuators of these diaphragms are either of plastic tab or steel pin.

Each iris diaphragm consists of leaves and the case. For different applications leaves are made from either hardened spring steel, stainless chrome nickel steel or stainless steel. For producing the case, corrosion resistant aluminium alloy is used. Fine mat black look is achieved by black-anodizing its surface.

Numerical aperture formula

Unmounted iris diaphragms are ideal for OEM applications, please note that these diaphragms have no mounting holes and cannot be mounted directly on a rod. Diaphragms can be mounted using an appropriate mount or please have a look at our selection of mounted irises.

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