Steinheil Cassarit and Ultraviolet Photography

I’m finding ultraviolet photography to be one of the biggest challenges I’ve come across in the photographic process in years. Such a huge learning curve.

Due to the short bandwidth of ultraviolet light, the reflective transmittance doesn’t seem to travel as far as visible light, plus this also causes a focus shift issue as photographing in infrared does.

With the sensitivity of the converted camera, I have been able to pick up the ultraviolet spectrum at a decent iso (around 800 – 1600 as opposed to 200 – 400) and live view permits achieving a fine focus if I take the time to really review and adjust before I shoot.

More of the problem seems to be in the lenses. Glass, air space and the cement used to join elements in a lens all interfere with the UV transmission. True UV transmission lenses (made with quartz-fluorite elements instead of glass) are still manufactured and a few older ones can be found second hand but these are way beyond my price range at an approximate cost of $3000US and up.

Fortunately ultravioletphotgraphy.com has a list of true and “accidental” lenses for ultraviolet photography work. I managed to pick up one of the Steinheil 50mm Cassarits recently and imediately noticed a difference. While not a spectacular shot, it is the first time I’ve been able to achieve focus on any subject farther away than about six inches.

Cat Photography, Animal Photography, Cat, Steinheil Cassarit 50mm, Pentax K1, UltraViolet Photography, UV, UltraViolet, U360 Filter, 360nm Photography, Fine Art Photography

This was shot midday 1/4 second, f8, iso 1600 using a Hoya U360 and S8612 bringing it to around a 360-365nm light source. The Steinheil triplets have been tested to have a cutoff of around 320nm. I am looking forward to testing this lens (as well as an older Cassarit 100mm) with a Hoya U340 to see if I can achieve a deeper UV cutoff point.

Cat Photography, Animal Photography, Cat, Steinheil Cassarit 50mm, Pentax K1, UltraViolet Photography, UV, UltraViolet, U360 Filter, 360nm Photography, UV false Color, Fine Art Photography

Here is the same photo with false color applied.

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