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

Today about a faster filter for reflected UV photography, as there seems to be demand for handheld UV shooting or shooting at higher speeds for instance for video work. After having thought about that for a while and about the whole chain light-object-filter-lens-sensor, an idea for a new filter came up, the XNUV, that I finally tested for the first time now using the Baader-U UV pass filter for comparison, a CERCO 94mm quartz flourite lens and my UV sensitive camera. Here presented in black and white diptych form, as the colors really don't matter for scientific work.

[click on image to see a larger one]

The used R. hirta flower is reflecting from 320 - 420nm with a distinct peak around 365nm at its petal tips and creates a very distinct UV bullseye pattern and UV nectar guide for its pollinators and that serves nicely as test object here.


Now on to the test results...
Ultraviolet (UV) image using Baader-U left) and XNUV filter (right):


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


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


What is important to notice is, that the XNUV is also able to precisely reproduce this distinct UV pattern as well as it shows a quite improved sharpness as compared to the Baader-U filter. And most importantly it is 3 stops faster than when using the Baader-U filter, which is a very impressive result as it will make it much easier also for video work.

I will report more about that filter here later, as more testing 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

Rudbeckia hirta: human vision vs simulated bee vison; reflected UV ultraviolet photography V

Well today I modified my high power flash for even more UV output. So a few test shots using as target a R. hirta as I have shown before in its multispectral representation. I took some shots in normal human vision VIS, in UV using the Baader-U, my all proprietary filters Jupiter-U and Saturn-U (300-350nm) filter, as well as in simulated bee and butterfly vision using my XBV2, XBV3 and XBV6 filter respectively.

[click on image to see a larger one]

Visual shot - human vision: Simulated butterfly vision using XBV3 filter: Simulated butterfly vision using XBV2 filter: Simulated bee vision using XBV6 filter: UV using Baader-U filter: UV using Jupiter-U filter: UV using Saturn-U (300-350nm) filter: IR (basically) as it was shot using only a ND filter: About all Rudbeckias and also this R. hirta have a very prominent, otherwise invisible "bullseye pattern" which gets nicely visible in UV (around 360nm) and bee vision (BV). Since leafs (petals were leafs one) reflect from 700-750nm onwards, that pattern is also invisible in IR.

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