UV-excited lume shots

Having recently purchased a 38-LED 2-Watt UV lamp, I decided to take some lume shots. UV light is best for charging photo-luminescent paint, see my article on watch lume. Here's the set-up:



When I switched on the lamp, the watch lume glowed like it was on fire!! However, the first shot was a little disappointing and there seemed to be no camera setting that brought out the brightness. It seemed that the UV itself was messing up the shot by over-exposing the camera sensor in spite of the UV filter on the lens:



So, I tried charging up the lume and then switching off the UV lamp before taking the shot. I ended up with 5 seconds exposure at f/22; consequently, much of that prized initial brightness was lost (f/22 is my standard aperture setting - I leave it there for a good depth field from the 60mm macro lens). Had I shot at say f/8 for a shorter time, the lume would have come out brighter. Still, even at f/22, the resulting pictures came out well and were combined in Photoshop without any processing other than cropping and re-sizing.

A re-lumed 1900's Trench watch:


A re-lumed Hamilton GG-W-113:


A Hamilton MIL-W-46374D with replacement Luminova hands:


In the last shot, the lumed seconds hand sweeps through the 5 secs exposure and the rapid fall in brightness of Luminova, even during that short time, is quite evident.

Best regards,

xpatUSA

An Accidental Sparkle!

As I recall, you can buy a special filter to get the sunburst effect - but the tiny sparkle below, just above the balance jewel, was completely accidental and no filter was used!



My setup uses three lamps, hence the six-pointer. You'll notice that the angles between the points and the point intensities are not equal because of my unequal lamp placements and distances.

So, how did the sparkle appear? The light from each lamp hits the curved bevel on the regulator and is reflected up into the camera's field of view. Even though the lamps have diffusers on them, the single curvature concentrates the reflected light and gives a fan shaped reflection beam rather than a spot beam. The "accident" occurred due to the exposure setting used. It was enough to saturate the image at the center of the sparkle but to have less and less saturated area going outwards along each reflection beam.

cheers,

xpatUSA