• Ultraviolet Photography

Time lapse of melting ice cube in SWIR

Infrared SWIR
21 replies to this topic

#21 dabateman

    Da Bateman

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Posted 26 February 2021 - 05:18

I would first try a different lens than jumping to think the triwave has an unusual sensitivity curve.
Coatings on lenses can have rapid dips.

See if this loss of signal occurs for each of lenses first. I thought you had a good SWIR lens from thorlabs? That shouldn't have a coating issue if there is something on the Wollensak.

#22 Andy Perrin


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Posted 27 February 2021 - 02:08

I have multiple Thor Labs SWIR AR-coated lenses and all of them behave this way at 1250nm.