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The circular variable neutral density filter (ND Filter) wheel is a device to linearly attenuate light as the filter is rotated. The filter can be used for white light as well as for lasers. A large finite aperture can be attenuated by counter rotating two filters in series. Sizes are available from 25 mm to over 200 mm in diameter. The useable wavelength range is from 375nm to 2000nm.
Reynard Corporation standard parameters apply:
Material: BK-7
Thickness: 2mm +/- 0.2mm
Surface Quality: 80-50 Scratch & Dig
Flatness: < 2 Fringes / Inch @ 632.8nm
Parallelism: < 3 Arc Minutes
