Jump to content
Sign in to follow this  
Kip Kubin

Black Light Question

Recommended Posts

I'm DP'ing a video on RED and there is a scene using black light shining on a wall.

 

Has anyone shot black light on a Red anything I should watch out for?

 

The black lights are 400 watt UV Flood Stage lights rented from a stage supply and touring company in Nashville.

 

Does anyone know what the lighting = would be in terms of a tungston light

 

Does 400w = 400w in black light

 

Any thoughts and help would be appreciated

 

Thanks

 

Kip

Share this post


Link to post
Share on other sites

Fortunately with the Red, you'll see what you have during the shoot, so you can adjust to make things work. Go by your monitor and

histograms.

 

Black light is outside the visible and shootable part of the spectrum, it works by getting converted into the visible range by certain materials. That process is very inefficient, so it'll be a lot less light than you'd get from a visible 400 Watt unit. In those small areas, though, it'll be a light source in frame, sort of like distant Christmas lights or neon signs.

 

 

 

 

 

-- J.S.

Share this post


Link to post
Share on other sites

Hi,

 

I shot something recently with Blacklight (F35) and the amount of light you need or "exposure" is almost unfathomable (obviously i didn't realise this). A double 4ft Batton needed to be about 1/2 a foot away and the 400W stage lights we had were also quite limiting - direct at the talent from a couple of feet away.

 

Great for CU's - would hate to be doing a bunch of wide shots. Works really well with the white teeth and eyes - grab some fluoro paint and dabble it on things you want to pick out - but as John said - good its digital so you can actually see what you're working with.

 

Regards, James

Share this post


Link to post
Share on other sites

400w doesn't really equate to anything, it's the power consummation of the fixture. What you want to look at is the photo metrics of the fixture. It will tell you how many lumens you'll have, at "x" distance. What's the beam shape and spread? How large of any area are you trying to light? You should be relying on your Gaffer to get you the look you want and the exposure your camera needs.

Share this post


Link to post
Share on other sites

A photometrics chart will tell you how much UV you're getting onto the phosphors. But the phosphors are a wild card, the next step in the process. You'd have to know how efficiently they convert UV to visible. With enough UV, you can saturate some phosphors. More UV won't get you any more visible light beyond that point. In fact, most flourescent lights are designed to operate a little beyond phosphor saturation, so you get a constant output.

 

Anyhow, this is all too complicated. The thing to do is simplify it by using the camera's histograms and the monitor.

 

 

 

 

-- J.S.

Share this post


Link to post
Share on other sites

Geez you are right.. I was too fast to reply... when shooting Film, you'd would have to go with your Spot Meter. I remember doing it that way the one time we incorporated black light.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  


  • Gamma Ray Digital Inc



    FJS International



    Abel Cine



    Broadcast Solutions Inc



    Tai Audio



    Visual Products



    Glidecam



    Paralinx LLC



    Metropolis Post



    Wooden Camera



    Media Blackout - Custom Cables and AKS



    Rig Wheels Passport



    G-Force Grips



    Serious Gear



    Just Cinema Gear



    New Pro Video - New and Used Equipment



    Ritter Battery



    CineLab


×
×
  • Create New...