Here a recent test I made to see if my newly developed High Power UV Flash would be able with just one pop to stimulate UV induced visible fluorescence. I used the X35 lens at f8, 1/160 exposure time and a Xcut blocking filter (prototype) ,which only allows 400-650nm vivible light to pass and thus also controls the risk of IR leakage coming from the flash, since Xenon emits plenty of IR. The flash itself is modified for high UV output and uses a quartz flashtube plus a UV transmissive, visible light blocking filter.
The following pic is (C) Michigan State University and shows clearly the high IR output of a normal Xenon flash (red line). The blue line however shows the effect of a flash circuit modification, allowing more amps per square centimeter to pass through the Xenon plasma, so as to enhance UV output and suppress the usually high IR content.
Here now the shot and the proof that the High Power UV Flash idea works to stimulate visible fluorescence:
[click on image to see a larger version]
And now how fluorescent minerals look like using that flash.
All fluorescent minerals from the famous Franklin Mine/USA:
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