• Ultraviolet Photography
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Bold claim - Hitech ND filters and UV capability

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#41 Pedro J. Aphalo

    Pedro J. Aphalo

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Posted 14 January 2019 - 09:43

Now a different Firecrest ND 1.2 (rectangular 67 x 85 mm) measured with a spectrophotometer (HP 8453) using tungsten + deuterium lamps. Range 200 nm to 1100 nm. At short wavelengths the glass used as substrate for the coating becomes relevant, and transmission drops to below the detection limit of the instrument. Apparently the increase in transmittance between 400 and 350 nm in my earlier measurement was not due to stray light.

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I doubt an ND filter will be useful for UV photography, flatness in the NIR is of more interest, I think.