Blacklight Filming & Exposure

Lighting a music video in two weeks, DP is interested in doing some stuff with blacklight, and possibly fluourescent body paint. Will have opportunity to shoot test, but wondering what experiences folks have had with this. Particularly, what gels you used for lights. DP says he thinks Lee 181 (Congo Blue) will work for this purpose. Any suggestions/caveats/tips or tricks?

Thanks,

Damon

Call Wildfire, Inc...they have numerous black light lamps for rental that are perfect for what you are doing. The number is (310) 645-7787 or (800) 937-8065

Good luck

OO Ken Glassing '[ ]

Dear Damon, Last fall I shot a short that had a blacklight scene. Unfortunately, I did not have the benefit of this list, and what the cinematographer's manual had to say did not help much.

Here is what I did - The room was about 10' by 15'. I used five blacklight (fluorescent) fixtures set at even intervals in the room, with another that I had mounted on a C-stand to fly anywhere I needed it. Also had a single 600W redhead with a green gel used to set the lead apart from the rest of the set/action.

Fluorescent paint was used for make-up. White as a base and other colors for accents (eyes, cheeks, hands, etc.)

The clothing was a sheer white material that really popped in the blacklight, along with some scarves and other strips of material coated in the fluorescent make-up and/or paint (I can't recall which worked better).

I was shooting 16mm with Fuji 500T. My spot meter gave me about a 2.8 on the clothing and a little under that on the faces. The lens was a 5.6 kinoptic wide open at 2.2. The cinematographer's manual specified a certain gel (I don't have my manual on me) that is used to filter UV from UV fixtures (The idea is to get the fluorescence of the reflecting materials and not the UV itself as it will fog your film.). Our production designer found it somewhere in LA. We rubber-banded it to the lens, but in retrospect, I believe your run of the mill UV filter will work.

And to finish it off - fog - which resulted in a really thick bluish haze thick enough to completely conceal the talent as they walked in and out of it.

It was not exactly what I had envisioned, but considering the budget, little time, and no opportunity to shoot tests, it turned out extremely well. (no one was more surprised than myself.)

Hope this helps.

Brent

A query on calculating exposure for uv light. I'm testing with a double bank 2 foot fluro with UV (blacklight)tubes and am getting f2.0 @ 200ASA

@ 1/4 second on a gray card, with my Minolta F spotmeter.The light is about 18 inches from the subject. Not enough to read with my incident meter, and suggesting the need for a huge blacklight source for my actual job, which requires the uv lighting up of a set.

Testing so far has produced only underexposed results. Even when opening

up two stops on the gray reading, the "glowing whites" that the director is after are only just there. Eventually the subjects will be people in white t-shirts, has anyone had experience washing the shirts in a whitening/brightening washing powder to increase the phosphoresence?

One thing to keep in mind with blacklight - the light that you see and record is based on retroreflectance. You can't measure it with an incident meter - only a reflected meter reading will give you an accurate reading of what you'll be seeing. Also, depending on the pigments that the light is retroreflecting off of - you will get extremely varying exposure levels -- it's the same as luminance values reflected from "regular" light sources, if you ignore the colors and merely think in terms of reflectance (IE a dark blue might retroreflect back more light than a yellow based on the pigments in that color that will reflect the UV as visible light).

All the best,

Jay Holben Director of Photography Los Angeles, CA

http://www.imaging-the-future.com/

Blacklight is reflected light, so don't try to read it with an incident meter. And unfortunately, the Minolta spotmeters do not do a good job of reading blacklight. The M is a little better than the F, but neither can be relied upon at all.

I use the Minolta spot F for reading tungsten light, but to read blacklight (or heavily colored light or TV or computer screens) I use a Pentax digital spotmeter with the Zone VI color-balancing modification. And even with the Pentax Zone VI you will get only an approximate reading for blacklight. You will tend to get more exposure than the meter reads. From experience I have learned to eyeball it. Turning on a tungsten reference light has helped me. As has testing. For a big set we have put blacklight tubes into Kino-Flo fixtures. Beware unwanted effects on human skin, particularly on hair (especially at the part).

Lowell Peterson ASC

Los Angeles DP

I shoot a lot of UV as well. I also use the Zone VI modified Pentax spot. Whether it's a wildly painted costume or prop or a red blue green UV matte screen, it's my meter of choice.

Eric Swenson VizFxDp

Aren't there high power lights that are much better to use for photography than flourescents? I've seen demo tapes by Wildfire, and 400watt and higher units in rental catalogs. I think I also saw some lights in the Altman Catalog.

I've never used those, but my couple of times trying to use flourescent illumination pretty much caused me to not try it again.

The one time I shot with black light- was for a graffitti doco. We shot an artist spraying a wall in a studio with his tag, using flourescent paint. I tried to reproduce the effect of the black light with and hmi and a combination of special filters but it didn't work- in the end we shot using 2 400k blacklight guns and shot it on time lapse. All I did was take a sample reading of all of the paints that would be used under the blaclight with my spot meter - sekonic and then I averaged out the readings- to the middle of the imaginery curve and then overexposed it by another 2 stops for safety. The results came out fine.

It could have been luck- we went to telecine so I'll never know.

Hope that helps

Matthew Woolf

UK dp

Both Wildfire and Altman sell (and rent) mercury vapor fresnels with UV filtration that gets rid of all of the visible light. That is probably what you have seen. An excellent source of rental of UV stuff is (are) the big theatrical rental houses in New York, Vegas, LA, etc. Production Arts Lighting and BASH are both heavy hitters in that game on the east coast (Bash also has a big rental outfit in Lost Wages, Nevada) There are also UV filters available for Strong Super Trouper carbon arc and Xenon follow spots. It is amazing what their mirror/lens array can get out of a relatively small source. If you need long throw and control, this may be a good way to go. It has been used in theater for ever for certain types of fluoro effects.

Regarding exposure readings, the reality is that the light source is the actual fluorescent pigment, not the lUV light source. Think of the UV light source as the "power supply" for the fluorescing minerals in the pigment. That is why incident light readings are useless - they are akin to pointing your meter at the power distribution box on set instead of the light:-)

I am interested in the Zone VI modification to Pentax Digital spot meters. I own this meter and have several questions. What exactly is the Zone VI modification? Where is it avaiable and in particular, can it be done in Canada or is it a specialty modification done by particular companies? Can the meter be used for regular spot metering when the modification is complete? Are there any other specialty applications that this modification would be good for?

Thanks. Any help would be greatly appreciated.

Andrew Gordon

Regina, Saskatchewan

Zone VI is a still photography company that publishes books and a magazine and manufactures specialty items for fine still photography. You send them your Pentax Digital spot meter and they will change the photo cells and make other internal modifications. The resulting meter will look and work the same, but your readings, especially of colored objects, will be more accurate. I tend to use a Minolta F for most of my work, but I bring out the Zone VI Pentax for reading colored light, blue/green screen, and television/computer monitors.

Lowell Peterson ASC

Los Angeles DP