XVUV - A Variable UV Transmission filter for reflected ultraviolet (UV) photography

Today about something rather unique, a variable UV transmission filter (XVUV) for reflected UV photography. Well, actually one with an adjustable / variable transmission shoulder which may be steplessly adjusted by some 20nm. I tested it for the first time now using the Baader-U UV pass filter for comparison, a UV-Nikkor 105mm quartz flourite lens and my UV sensitive camera. Light was sunlight on a bright sunny day.

[click on image to see a larger one]

Ultraviolet (UV) image using Baader-U left) and shortest possible setting of the XVUV variable filter (right) - architecture:


Ultraviolet (UV) images using XVUV variable filter at different settings with shifting peak transmisison towards the right (different whitebalance as above) - architecture:


Relative transmission spectra of the XVUV variable filter at different settings, illustrating its ability to prefer shorter UV wavelengths:


This filter now allows to steplessly shift the peak transmission from about 360nm down to some 340nm, albeit with some loss of peak transmission.

I will report more about that XVUV variable UV transmission filter here later, as more testing, calibration and optimization needs to be done.

Stay tuned, more will follow on that fascinating subject...

More info on this very interesting field may be found on my site http://www.pbase.com/kds315/uv_photos

XNUV2 - a much faster filter for reflected ultraviolet (UV) photography

Today about another, faster filter for reflected UV photography, as there still seems to be some demand for handheld UV shooting or shooting at higher speeds for instance for video work. This here is the XNUV2, that I finally tested for the first time now using the Baader-U UV pass filter for comparison, a UV-Nikkor 105mm quartz flourite lens and my UV sensitive camera. Light was late evening light on a rather dull day.

[click on image to see a larger one]

Ultraviolet (UV) image using Baader-U left) and XNUV2 filter (right) - flower :

bw image shows that the UV content is basically identical:


Ultraviolet (UV) image using Baader-U left) and XNUV filter (right) - architecture:


What is important to notice is, that also the XNUV2 is also able to precisely reproduce this distinct flower UV pattern, as well as it shows good sharpness, as compared to the Baader-U filter. And most importantly it is 2.3 stops faster than using the Baader-U filter, which is quite an impressive result as it will make it much easier for video work.

I will report more about that filter here later, as more testing needs to be done.

I have written before about a faster XNUV filter HERE

Stay tuned, more will follow on that fascinating subject...

More info on this very interesting field may be found on my site http://www.pbase.com/kds315/uv_photos