black lights turning green

[Kara Stephens]

I tried shooting some black lights on my xl-1 (tungsten setting) and they looked green on the monitor and through the eyepiece. Why is this and is there anyway to make them look purple on screen and still have them be effective? I'm trying to make a painting glow that was painted with flourecent paint.

 

thanks

[Alvin Pingol]

Balance for Daylight (5600K), or balance for regular fluorescents (usually some high Kelvin number plus MinusGreen/Magenta) before you go under the blacklights.

[John Sprung]

Black light is ultraviolet, so I'd test a UV filter -- maybe even stack up two or three of them. It looks like the green chip also has some UV sensitivity. If these are flourescents, it could also be the mercury lines.

 

 

 

-- J.S.

[John Pytlak RIP]

I agree. When shooting fluorescent objects illuminated by ultraviolet "black light", you should use a UV filter (e.g., Kodak Wratten 2B) over the camera lens. You want the film or electronic sensor to only "see" the visible light from the glowing objects in the scene, and not the UV light illuminating them.

[Kara Stephens]

thanks, I'll try the uv filter and the color balancing and see what works.

 

Kara

http://www.karastephens.com

[John Sprung]

thanks, I'll try the uv filter and the color balancing and see what works.

So how did it turn out? Be sure to let us know what worked or didn't. That way we all learn something.

 

Thanks --

 

 

-- J.S.

[Kara Stephens]

Nothing ended up working. I tried different color balancing, uv filters and a combo of both, yet the blacklight bulbs still appeared green. I could make the whole world look magenta but the bulbs were always green. I ended up using cool white tubes with a heavy purple gel on them to make it look like a black light. Weird.

[Phil Rhodes]

Hi,

 

I've shot loads of stuff with UV, and never had this issue. Shot on PD-100 and DVC-200.

 

Phil

[John Sprung]

Nothing ended up working. ... I could make the whole world look magenta but the bulbs were always green

<{POST_SNAPBACK}>

That sure sounds like the problem is the strong spectral lines of mercury. In that case, your solution of using visible light flourescents with gel instead of real UV's is likely to be the best.

 

 

 

-- J.S.

[Michael Nash]

I've heard "Congo Blue" gel can work for this. It's a pretty color on its own, but I've never tried to get objects to fluoresce with it. Can anyone back this up?

[J. Lamar King IMPOSTOR]

I've heard "Congo Blue" gel can work for this. It's a pretty color on its own, but I've never tried to get objects to fluoresce with it. Can anyone back this up?

<{POST_SNAPBACK}>

 

Yes, that works or use Lee 200 Double CTB over Daylight Kino's or Chroma 50's. Or use like a Full and a Double CTB over a Tungsten lamp. It won't be as radient as Black light but it will cause the paint to have an obvious glow. There is also a Lee filter called Zenith that transmits like 90% above 750nm.

[Phil Rhodes]

Hi,

 

Congo blue over HMIs will get fluorescent paints glowing; also, look into blue dichroic filters which are often found in intelligent lighting (which commonly have cold, discharge sources). Most of them are specifically designed to pass the longwave UV from the lamp to illuminate UV-active smoke particles for spectacular aerial effects, and may well work for you.

 

Pihl