# Blacklighting a Stage



## Omega (Nov 23, 2008)

Hello all,
Just registered at this beautiful place, though I've been peeping around for a while now.

Anyways, for an upcoming dance concert, I would like to use blacklight. I was wondering that if I had six 4' 40 watt blacklights, would that be enough to cover a stage with a width of 40' and a depth of 30'? Not sure how exactly I'm going to end up placing them, but probably spread four of them downstage and hang the other two from a batten. Would this provide an adequate wash? And if so, what about if I include the apron for a combined depth of about 50'? The apron won't actually need to be lit but it will save my backstage techies from placing and taking off the lights before and after the one dance. Or maybe I should place all the lights on my battens? (I'm sure working out how to cramp 24' feet of blacklight into my already cramped battens will be just joyous. )This would be a drop of about 25' from the stage to the batten.

And then I've heard that there are some gels that provide a decent substitute for actual blacklights? What are these gels (besides the wood's glass filter) and how well do they work in lieu of blacklight? I'm trying to do this without renting anything but if that's what it comes down to, so be it. 

Sorry if this topic is supposed to go in the fx forum...?


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## renegadeblack (Nov 23, 2008)

I haven't ever actually blacklit a stage, but from what I've heard in other threads, the gels work extremely well. Something that we were going to use once but the director didn't like the 4 minute warm-up time was a couple of 400w UV cannons as they were called. I found them to be absolutely amazing, they made out black-painted wooden stage look like there wasn't a drop of paint on it. I'd probably look into getting some of those instead being also as they would save you some space and they also have some pretty impressive throw.


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## Sayen (Nov 23, 2008)

What do you want the audience to see with the blacklight effect? There are some dark blue gels that work very well - hopefully someone here remembers the name, or I can dig out my forms at work next week. They will cause certain fabrics to appear to glow, but it's not quite a UV effect. One of my crew threw them into work lights by mistake, and we found out when they lit up individuals entering the stage for set changes.


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## icewolf08 (Nov 23, 2008)

When you say you have six 4' blacklight tubes, I assume that you mean fluorescent tubes. This is actually a much more efficient way to get UV out on stage, especially compared to using gels as mentioned above. Will it be enough to fully cover your stage? I am not sure, while the fluorescent blacklights are actually very good at outputting blacklight, they do so in every direction, thus are very diffuse. If you have or can fabricate some mirrored reflectors to get some more directionality from them, that would help.

The question as to what kind of effect you want to create is very important. Are you trying to make dancers "disappear" so that you only see hands and feet or are you trying to highlight UV painted costumes or something else? If you know what effect you are trying to create you can place lights and test it out and see if you have enough punch to be effective, and it is quite possible that you will.

If you set up a test and it doesn't do what you want, there are a few options. First would be to get more fluorescent blacklights. Second would be to go to your local theatre supplier/rental shop and see if they have any higher power UV floodlights for rental. There are many available, but I am a fan of the Wildfire units. I would only turn to gelling normal fixtures as a last resort as it is the least effective simulation of blacklight.


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## Clifford (Nov 23, 2008)

I had to light a space similar in size (40'x26' plus 6' thrust)for a dance concert last year with black-lights. We had 3x3' black-light florescents downstage on the thrust. The dancers were wearing all black except for white Phantom of the Opera-like masks and white gloves. Even with only those fixtures, the stage was lit pretty well (insofar as black-light 'lights' a stage), and the desired effect was created. So if you're doing something like that, it worked for me.


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## derekleffew (Nov 23, 2008)

Omega, I can virtually guarantee you're going to be disappointed with your six 40W fluorescent UV tubes, particularly trying to cover that much real estate. I've found them to be ineffective unless within 10' of the object being lighted. It goes without saying that EVERY other light in the theatre MUST be *off*, and the longer the act continues, the more the audience's eyes will become accustomed to the darkness and the less dramatic the effect will be. Eyestrain may also become an issue.

Colors such as L181 Congo, and R59 Indigo can, sometimes, produce a simulated blacklight effect, but not a true one. Remember that true UV light, at 400nm and below, is outside the visible spectrum, and thus much horsepower is needed to get through that Wood's glass. Incandescent and even fluorescent sources are lacking in the spectral distribution wavelengths necessary to produce UV, thus most professional luminaries use short-arc sources. Even with a 1200W short-arc source in a $10K moving light, mixing Congo with the Magenta and Cyan dichroic filters does not produce the same effect as using a Wood's glass filter. True UV light is not visible to the naked eye; we only see the effects of it when it causes a dye or pigment to fluoresce. 

See Wildfire Lighting & Visual Effects for more info, and for the best fixtures and materials for this type of effect in the industry. 

I don't mean to sound like a naysayer. Since you have the fixtures, set up an experiment. But be prepared with a plan B, which most likely involves renting at least 4-6 of these:


at a cost of $300/each per week. Altman makes UV fixtures also, which may be less-expensive to rent in your area. Note what they say about their 40W tubes: "Effective distance for the #701 is 4 to 10 feet from the subject."http://www.controlbooth.com/forums/members/omega.html


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## Omega (Nov 23, 2008)

> When you say you have six 4' blacklight tubes, I assume that you mean fluorescent tubes.


Yes.
NEW CASE HALF DOZEN 4 FOOT BLACKLIGHTS 6 48" PARTY E1 - eBay (item 370115708801 end time Dec-18-08 09:31:17 PST)


> The question as to what kind of effect you want to create is very important. Are you trying to make dancers "disappear" so that you only see hands and feet or are you trying to highlight UV painted costumes or something else?


Gloves, white(ish) dresses, and some UV makeup, most likely.


> It goes without saying that EVERY other light in the theatre MUST be off, and the longer the act continues, the more the audience's eyes will become accustomed to the darkness and the less dramatic the effect will be. Eyestrain may also become an issue.


All in all, the piece will be around four minutes. When the blacklights are on, all other lights will turn off (except any blacklight gelled fixtures). And you probably know how dance concerts are; if the parents can't pick our their children's faces perfectly, they complain to the instructor - meaning even in my most stylish and moody pieces, I have to throw in a minute-long bright wash on the entire stage. So it shouldn't be an overkill with the blacklights. I'll mix in some other stuff, perhaps cool washes or strobes. Since it's so short, I'd probably rather have a more conventional lighting rather than renting a couple hundred dollars worth of UVs; though one day, I'd love to give it a try. As long as the dancers keep a fair distance from the cyc, that should limit the depth to a little over 20', if the blacklight tubes could work with that.

And are the wildfire units instant on? I've heard some of the UV lights can take up to ten minutes to reach full intensity. I don't have the tubes yet but they're being sold on ebay for $130 and I figured it would be nice to have some effects like those ready for when we want them instead of heading downtown to the rental store. And I know I have a Congo gel on my one intelligent light, so I'll see the effect that has. Never knew what it was for before now as it's such an ugly and dull color - though since it can be seen fairly well I'm sure it's not the suggested shade of congo blue. 

Maybe I'm being naive here, but is there a reason the lamp manufacturers can't just make black lamps for ellipsoidals and fresnels?  I'm sure they'd be pretty popular.

And thanks for the optimism, Clifford. Seems to work differently for everyone so I'll see my result.


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## cdub260 (Nov 23, 2008)

I've used blacklight for shows in both of my venues. The smaller of the two is a 236 seat theatre with a 24 ft. by 24 ft. proscenium arch stage with a 4 ft. thrust. I've blacklit this stage with three of the fixtures you propose using for your theatre. It worked fairly well. I got good coverage with one fixture coming from a down stage position and the other two from a mid stage position. The next time I did blacklight on this stage I added a Wildfire Effects Master coming from my AP position. This worked even better, though it also blacklit a portion of the audience. Bear in mind, however, that all lighting positions in this theatre are within 15 ft. of the stage. As Derek mentioned, the fluorescent tube style of blacklight has a limited throw and is best used in close quarters.

Effects Master VHO Fluorescent Fixtures

On my main stage, which is a 2600 seat amphitheatre, I've put together blacklight effects for the Pageant of the Masters using a combination of Wildfire's Effects Master and Long throw series of blacklights. With some of my hang positions farther away than in my other venue, I've found that the Long Throw fixtures are generally more effective in this space than the Effects Masters.

So, if you're hanging these relatively close to the stage, the blacklights you have should be adequate, but if they're more than 20 ft.from the stage, which is pushing it, I would look into long throw fixtures. If this is not within your budget, try getting creative with your lighting positions. Consider setting your existing fixtures up as footlights, or place them in boom positions in the wings, anything to get them closer to your performers.


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## cdub260 (Nov 23, 2008)

Omega said:


> And are the wildfire units instant on? I've heard some of the UV lights can take up to ten minutes to reach full intensity.



The Wildfire Effects Masters, being fluorescent fixtures, are instant on. The Long throws in my inventory take about a minute to warm up to the point where they have decent output, though they are not yet at full intensity.


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## renegadeblack (Nov 23, 2008)

Omega said:


> Maybe I'm being naive here, but is there a reason the lamp manufacturers can't just make black lamps for ellipsoidals and fresnels?  I'm sure they'd be pretty popular.



That sir, is the question! I would love to have some blacklight bulbs for those! Anyone wanna do a weekend project?  I saw an old S4 bulb that was burnt out (atleast I'm hoping it was) that someone colored blue with a sharpie, similar effect possibly?


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## lieperjp (Nov 23, 2008)

You _can_ do it, but like others said, you will be disappointed. Last year during Wizard of Oz, they wanted me to use black lights for the haunted forest. For some reason, we had four fluorescent lights - so eight 4' tubes. They were hung about 18' above the stage. We also coupled them with 70w black light fixtures in our Altman R40 strip lights along the front edge of stage. We got black light, but just not the amount we were looking for. 

You probably will want to get some more powerful lights, or at least more of the less powerful lights.


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## derekleffew (Nov 23, 2008)

Omega said:


> ...Maybe I'm being naive here, but is there a reason the lamp manufacturers can't just make black lamps for ellipsoidals and fresnels?  I'm sure they'd be pretty popular....




renegadeblack said:


> ...I saw an old S4 bulb that was burnt out (at least I'm hoping it was) that someone colored blue with a sharpie, similar effect possibly?


Not even close.

One of the problems is the glass in conventional lenses filters out the UV wavelengths. Also, as I said previously, the incandescent lamp does not produce the proper UV energy.

These fixtures may appear to be standard ERSs/Fresnels, but they have an arc lamp which requires a ballast, and special lenses/filters, hence their high cost.


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## n1ist (Nov 24, 2008)

One way of getting around the long warmup time of the merury vapor bulbs is to use a dowser, either remotely controlled (dmx to servo controller with a servo moving a flag; I seem to remember that someone made one out of a dead CD-ROM drive) or manually.


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## CavezziMagnum (Nov 24, 2008)

You have a few options for blacklight. I shall list them from least to most expensive:

1) R57 sometimes can work as a blacklight. Congo.

2) 8' Flourescent Blacklights are great! Buy a couple fixtures, and group them together. My personal rule of thumb would be (1) 8' fixture per 10 square foot of stage.

3) BLACK LIGHT CANNON! either a cannon or a high-output blacklight fixture. Extremely effective, extremely expensive. (relatively)

Good Luck!


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## gafftaper (Nov 24, 2008)

n1ist said:


> One way of getting around the long warmup time of the merury vapor bulbs is to use a dowser, either remotely controlled (dmx to servo controller with a servo moving a flag; I seem to remember that someone made one out of a dead CD-ROM drive) or manually.



The CD-ROM dowser is for use on a video projector. It would be too small to effective dowse a typical UV cannon. 

I purchased a set of Elation UV Wash Lights for my space. They take less than a minute to warm up to full. 100 Watt UV compact fluorescent lamp. A nice reflector. You have to buy a mini-c clamp or drill out the yoke to fit a standard one. Price should be around $125 depending on the package your dealer puts together. No they aren't Wildfire products in terms of output and durability but for occasional use they are pretty good 

If you have some housings around with a good reflector, you can also buy just the lamp for around $40 each. But they are quite long so I kind of doubt you have something in house they will fit.


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## Grog12 (Nov 24, 2008)

R57? R57? Really? Come on if you're going to do black light with out going out and spending money on any of the above mentioned items use R382, Congo Blue baby. Works well...not as good as a tride and true machine but still a good effect.


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## BillESC (Nov 24, 2008)

+1 on the Elation UV Wash. We cover a 20 x 30' area with one for a dance recital. Two would do the job for you.


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## lieperjp (Nov 24, 2008)

+1 for the Elation UV wash. We were looking at these last spring for the dance scene in our Children's Theatre Production. I'm trying to find what we actually purchased, I think they were American DJ 300watt Blacklights, which are HUGE, kind of heavy, but pretty powerful - cut through extremely minimal stage lighting. If I can find a link, I'll post.

Just for clarification, what is the difference between a UV/Blacklight Wash and a UV/Blacklight Cannon? We spoke with a special effects guy and he was telling us if we were looking for a wash, we should use a wash fixture, cannons are for more specific locations - therefore more are needed to provide a sufficient wash.


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## gafftaper (Nov 24, 2008)

Lots of terms being thrown around here in different ways by different manufacturers here are the main options: 

Wildfire FX builds long throw black light instruments. VERY expensive to purchase. But you can mount them 50 feet from the stage. 

Then there are a variety of products that look like a large bucket or box they use a 400 watt HID lamp. These have a really high output but they take 5 minutes to warm up to full intensity. It takes 2 or 3 minutes before you even see it. Once on full, they produce a HUGE amount of light. I think they run around $500 each. 

Compact fluorescent black light in a small box. Comes on at about 70% about a minute for full intensity. Elation's is excellent. Bright. Good coverage. Price under $150 depends on the package... call your local dealer or send a pm to BillESC. 

Finally, there are fluorescent tube lights like you get at a party store. They are great but as Icewolf mentioned earlier there is no reflector so the light goes in all directions and is quickly lost. Cheap... but not very effective unless you use a lot of them. 

Gaff's Recommendations:
-Wildfire is the best solution for a permanent install or for a show with a big budget and very high standards of perfection. 
-HID buckets are a great rental solution for a show and produce a ton of UV.
-Elation UV Wash (and similar products) are a great choice for purchasing for those of us with smaller budgets and moderate expectations. Lot's of output, easy to store. The cost of purchasing vs. renting 2 or 3 times makes them a good buy. 
-Can't recommend flouro tubes for theater in most situations.


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## tcsta (Dec 15, 2008)

My theatre just staged Willy Wonka and used long-throw blacklights for the scary boat scene to great effect. Wildfires are the best, but the 2 we purchased were excellent. We bought 2 Chauvet Black Shadows for $240/ea. They were mounted about 20 feet from the stage and they lit extremely well. Pay close attention to what others have said about warm up time and dousing. You CANNOT hook these type of long-throw lights to a dimmer. Our solution was simply to turn them on at intermission to allow them to reach full intensity. With normal stage lighting, the UV isn't noticed at all until the stage lights are dimmed.


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## jmac (Dec 27, 2008)

lieperjp said:


> You _can_ do it, but like others said, you will be disappointed. Last year during Wizard of Oz, they wanted me to use black lights for the haunted forest. For some reason, we had four fluorescent lights - so eight 4' tubes. They were hung about 18' above the stage. We also coupled them with 70w black light fixtures in our Altman R40 strip lights along the front edge of stage. We got black light, but just not the amount we were looking for.
> 
> You probably will want to get some more powerful lights, or at least more of the less powerful lights.



Also used black lights for W. Oz haunted forest and jitterbug scene. Outdoor stage about 40' wide by 20' deep. We rented, and asked for 8 of the Elation UV Washes which looked like they would perform better than standard fluor. strips, as others have said here (not enough punch). Not sure we needed 8, but wanted to be safe. 

Rental company switched us to 4 Altman 705's (400W MH). These did a very good job, connected to non-dim's. We turned them on 3-4 minutes ahead of time to warm up (you don't seem to notice them much if enough other lights are on), and when the time came, dropped the other lights, leaving just the black lights on. So we didn't need the dowsers. But if you need to turn them on and off repeatedly, you probably would need the dowsers, to avoid re-strike issues.


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## Vic (Dec 29, 2008)

Hi,
Dark Blue gels are generic # 119. I have noticed the same effect on the Irish Dance costumes I work with.


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