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I've had my Sony NEX 3 camera converted to full spectrum and I really like what I can do now.

In a previous question, I was curious as to how I could revert the camera to shoot visible light using filters.

I am now trying to figure out how to use filters to make the camera see only UV light with filters. I am trying to get results like this or like this.

What filters should I use to restrict a full spectrum-converted camera to UV spectrum?

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The B+W 403 is the obvious start; it is the only UV pass filter readily available

Note that:

  • the filter has a small IR leak, so you might want to combine it with a IR stop filter if sticking to UV only is important; a picture of a transmission curve is better than a thousand words (via dpreview.com - watch out for the second peak just over 700nm).

enter image description here

  • the image will out of visible spectrum, you would need some serious false color work or B&W conversion

  • a glass lens will go only into very near UV spectrum (~300 - 400nm), to venture outside of this zone you need some very special optics, as medium and short wave UV are blocked by glass (and air, to some extent).
    On the other hand this is the part of UV spectrum that is visible to birds and insects, and thus is the most fun to photograph in nature.

  • I think this is the best answer so far, but I would love maybe a recommendation in point 1; point 2 needs a bit of clarification and/or links; and the 3rd point isn't clear to me (to venture... outside UV spectrum?). Is this answer for BW or color results? – MicroMachine Mar 19 '18 at 17:36
  • @Micromachine, both: normal glass absorbs UV below ~350 nm, which means that anything but UV wavelengths close to visible light won't reach the sensor. It doesn't matter after that if you work in color or in B/W. In chemistry, we had to use quartz cuvettes when we needed shorter wavelenghts... – remco Mar 19 '18 at 17:50
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    Clarified the points one and three; the point #2 is more challenging for me to explain - what I meant is that you have sort of one extra color, but as all colors of human vision are already "taken" you can either map the extra color space to an existing color (i.e. false color work) or disregard wavelength / color information altogether and record only intenstity (i.e. BW conversion). The first approach was taken by OP example #1, the second by OP example #2. – Jindra Lacko Mar 19 '18 at 18:01
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    No, I meant that without a special lens you can shoot ONLY bird / insect vision, but no further. – Jindra Lacko Mar 19 '18 at 19:06
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    oh no! The B stands for Biermann and W stands for Weber. It is a German (formerly West German) photo filter manufacturer, now part of Schneider optics. They really know their glass, only Hoya in Japan coming close. Have a look at their brochure here: schneideroptics.com/pdfs/prices/BW_brochure.pdf – Jindra Lacko Mar 19 '18 at 20:37
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Evident answer: a filter that blocks the part of the spectrum you do not want to record...
An exemple of such a filter would be the "B+W Slim UV Black (403) Filter". Note that such filters appear as a sheet of black (opaque) glass :)

You might run into other issues, like your lenses blocking too much of the UV wavelengths you're interested in (normal glass isn't all that transparent for UV)

  • You say some lenses block UV, so should I try with the Sony Kit lens or older, manual lenses? Which ones are less likely to block UV? Are there affordable lenses that can be mounted on Sony E-Mount that block UV less (except for pinhole... ) – MicroMachine Mar 19 '18 at 17:43

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