Shooting with blacklight

[Aaron Moorhead]

I'm shooting a music video with costumes that have ultraviolet strips on them. I'm shooting pieces of it on Phantom around 500 fps, so I assume I need a lot of punch to get those strips to glow, which is really tough to do with blacklight.

 

I've done a good amount of talking with people who have shot under blacklight a lot, and gather that it's basically all a reflective measure and there's really no way to ambiently measure the blacklight. How would you suggest that I get the biggest punch of of my blacklights?

 

- I have 5 10ks, I was wondering if I could use something like Lee Ultimate Violet or Lee Congo Blue ( http://www.leefilters.com/lighting/product...ours/showall:1/ ) on them to get the most punch, place them right behind camera. I might be just misunderstanding blacklights, though. Is it possible to convert a tungsten source to a blacklight with just a gel, or is it in the nature of the bulb itself? I know the light transmission on those gels is very stiff, which is why I was thinking of huge sources.

- Perhaps use blacklight tubes from Kino? If so, how do I avoid flicker, and also, how do I get enough exposure without dozens of banks of blacklight kinos?

 

Thanks for the help in advance.

[Sherman Johnson]

Hi Aaron,

 

I don't have any info on punch or actual light output for hi-speed work, but I might suggest contacting either Wildfire (http://www.wildfirefx.com) or Altman (http://www.altmanltg.com). Both have blacklights with some throw and I know that at least Wildfire is supposed to have some that are flicker-free.

 

- Sherman

[John Sprung]

A lot depends on how efficiently your phosphors convert black light to visible. Spot metering is the way to cancel out all the variables and know for sure what you have. Test and measure the proposed lights on whatever phosphors you'll actually be shooting.

 

Gels on tungsten are an extremely inefficient way to get black light. Test them against the flourescents. As for flicker, same as regular flourescents, you just want to avoid old fashioned magnetic ballasts.

 

 

 

 

-- J.S.

[Jake Kerber]

Congo Blue and Ultimate Violet will give you a look, but will not create a true UV source. In short, it will not really make phosphors glow.

You'd have to use Woods Glass, but with incandescent sources this method would be highly inefficient.

 

I'll second the wildfirefx recommendation. They are located in Torrance, CA and have a demo room filled with different lights and paints, and in my case, I brought a camera to shoot a quick test. They were helpful. However, testing their products only makes sense if you're going to be using their stuff because, I've

found that blacklights and fluorescent paint or makeup varies significantly.

 

Have you tested the fabric to see how reactive it is to UV light? Obviously, this will make a huge difference, as you could be pumping in all the UV light in the world and not getting the desired look because of the fabric, makeup, etc. itself.

 

500fps...good luck. Please let us know how everything works out.

[Aaron Moorhead]

We found some really awesome results (thanks to an on-point production designer) with Scotchbrite reflective tape and a 2 way mirror. Not the same as a blacklight, but works really well for what we're doing. Now the question is how to keep the light and mirror on the precise same axis as the camera as it zooms all around the set on a dolly and jib. We're thinking of removing the need for the mirror by using an LED ringlite. Anyone done this before? Testing it tomorrow.

 

We're still using blacklights, but the need for enormous light quantities of blacklight is no longer as important for the purpose we're using it for (the Scotchbrite replaced it), so we're just going to use 3 Kino fatboys with blacklight tubes in them and walk them right up next to camera. Thoughts?

 

Thanks!

 

Aaron