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Seamless Frusta Creation for Stray-Light Management in Optical Devices



Edward F. Kelley, Paul A. Boynton


Optical devices such as luminance meters and digital cameras used for light measurement often suffer from stray light corrupting the accurate measurement of light particularly when they are used to measure dark areas of high-contrast scenes. A method of controlling the stray light is provided using gloss-black frusta. Methods to create seamless frusta from plastic sheets are described and their use is described.
NIST Interagency/Internal Report (NISTIR) - 6637
Report Number


frusta, frustum masks, frustums, high contrast, luminance measurements, stray light, veiling glare


Kelley, E. and Boynton, P. (2003), Seamless Frusta Creation for Stray-Light Management in Optical Devices, NIST Interagency/Internal Report (NISTIR), National Institute of Standards and Technology, Gaithersburg, MD, [online],, (Accessed July 22, 2024)


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Created November 30, 2003, Updated October 12, 2021