# Using Projection as Stage Lighting



## JD (Jun 18, 2013)

Some thoughts about the future:

Although current LCD projection is subtractive in nature and therefore a very inefficient source, it would be shortsighted to believe powerful mega-pixel LED projectors that uses additive mixing will not at some point make it to the market. Below is a link to a Jack Conte music video that inspires the brain when looking into the future.

Projection has been used for a long time for rear screens, but outside of a fleeting effect, has rarely been used for front lighting. In the case of this video, the stage is very small (3' by 3') and the props even smaller. The immediate drawback is that it is a single point source. Still, I would imagine that as more sophisticated software is developed, a stage could be lit from many sources, with the masking math incorporated in the software. Are we seeing an inadvertent glimpse into the future of stage lighting? 

[video=youtube_share;TAJBc7gW-Vc]http://youtu.be/TAJBc7gW-Vc[/video]


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## sk8rsdad (Jun 18, 2013)

Hasn't High End been doing this for years?

DL.3 Digital Light - Digital Lighting - Products - High End Systems


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## MarfaLights (Jun 18, 2013)

That's some nice video work. I've thought of the possibilities in our venue. Put a dozen projectors on the back truss for wash and specials and movers and you'll create a hundred video programmer jobs!


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## JD (Jun 18, 2013)

sk8rsdad said:


> Hasn't High End been doing this for years?



Even that unit uses subtraction on the black-to-white scale, so you are lighting the whole stage and then blocking all areas except what you want lit. The result is that only a small % of the light engine output is actually being used. Still, in a smaller venue I am sure the intensity does the job. Remember, we would effectively be replacing S4s and Movers.

If a high output LED source could be created along the lines of a mega-pixel or more, then you are only putting energy into the LEDs in the matrix where you want light to be. That would be like taking a large LED video screen and shrinking it down to 2" by 2" source chip. A little beyond our current technology, but so were LED stage lights 10 years ago. I suspect heat is the biggest problem.


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## MarfaLights (Jun 18, 2013)

Totally inefficient means of lighting the stage for sure. Yet a fascinating area to study while the technology catches up. I worked with LEDs in the late 70s in engineering school and the thought of someday using them for traffic lights was discussed and seemed unachievable.

We can count on the cost of LEDs to continue to drop while the output goes up. A DLP chip is nothing more than a really tiny moving mirror. Instead of 40 movers over the stage, what if you had 100 LED DLP projectors? Let's take your example and say only a small percent of the light output from a single light engine was useful on one position. Now multiply that by 100 instruments in an array all having the appropriate pixels turned on to illuminate just the bass player. But wait, at the same time you can turn on the pixels in a different color on the keyboard. One frame of white light and you just strobed the stage with 100 instruments. That doesn't yet include the creative side of things where you mix video imagery into the lighting effects. 

The projector technology is there to do this as demonstrated by the video above. The biggest factor is software. If I were in grad school, I would do this project.


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## Footer (Jun 18, 2013)

....We have had several shows in my space that do this. We just had Pilobolus in, they lit an entire piece via a projector FOH. Dancers moved inside the content and were highlighted. _Wicked_ also does a lot of this using DL2's.


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## LavaASU (Jun 18, 2013)

It can be done with a big enough budget...

http://www.youtube.com/v/P1mjJTQPcrw

We also have an article on here about _KÀ_: http://www.controlbooth.com/forums/featured-articles/31255-projection-production-ka.html


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## Esoteric (Jun 18, 2013)

We have done that a lot.

Mike


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## len (Jun 18, 2013)

I've recently been trying to buy a DL or the Robe equivalent. There's a few out there, but there's 2 problems, I'm told reliability is an issue, and that parts are becoming more scarce. So even if the output were proper, there's a lot of other issues with them. And even with their flexibility as a light source, you need a media server and someone to program it, neither of which are cheap.


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## DELO72 (Jun 19, 2013)

JD said:


> Some thoughts about the future:
> 
> Although current LCD projection is subtractive in nature and therefore a very inefficient source, it would be shortsighted to believe powerful mega-pixel LED projectors that uses additive mixing will not at some point make it to the market. Below is a link to a Jack Conte music video that inspires the brain when looking into the future.
> 
> ...



For the majority of plays or stage productions (theatre/opera-- not concerts), I would say no. The color provided by Projectors is terrible. They use Mercury Vapor, short arc lamps (P-VIP), so the light emitted is very, very, VERY Green. The light emitted is HORRIBLE for skin tones with a CRI of around 70-75 max. If you are doing a stylized production where costume colors, set colors, and skin tones don't matter for that particular production or moment, then sure (if the single-point source issue isn't also a problem). But not for general use.

ps. I'm referring only to standard "Video projectors" and not the intelligent "movers" such as those used by HES. I'm not sure of which light sources those use-- so please take this post as being based around those standard projectors using PVIP sources. Also of note--Older Panni projectors use HMI lamps, and those put out a full spectrum and high >90 CRI.


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## JD (Jun 19, 2013)

DELO72 said:


> For the majority of plays or stage productions (theatre/opera-- not concerts), I would say no. The color provided by Projectors is terrible. They use Mercury Vapor, short arc lamps (P-VIP), so the light emitted is very, very, VERY Green. The light emitted is HORRIBLE for skin tones with a CRI of around 70-75 max. If you are doing a stylized production where costume colors, set colors, and skin tones don't matter for that particular production or moment, then sure (if the single-point source issue isn't also a problem). But not for general use.
> 
> ps. I'm referring only to standard "Video projectors" and not the intelligent "movers" such as those used by HES. I'm not sure of which light sources those use-- so please take this post as being based around those standard projectors using PVIP sources. Also of note--Older Panni projectors use HMI lamps, and those put out a full spectrum and high >90 CRI.



Thus my thoughts about a "future" LED matrix as a projection source. Current technology is not ready. The best we can do is use a bright source and block out what we don't need by using a LCD gate or multiple "mirror" chips. When the time comes that we can put a million LEDs on a chip, a lens in front of it, and keep it cool enough not to blow up, we will be ready. Such a "chip" is beyond us now, but the potential makes for stuff to dream about. The electrical efficiency of such a device would be something to dream about as well, since you would only be using power for whatever elements of the matrix you were driving. 

Someday... For now, it is cool to watch what I think is a small scale window into the future.


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## MarfaLights (Jun 19, 2013)

JD said:


> Someday... For now, it is cool to watch what I think is a small scale window into the future.



Could not agree more!


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## tladuke (Jul 7, 2013)

We have been working at developing a digital workflow for projection based theatrical lighting for over 5 years. The projectors are not the stumbling block. It is the workflow. Managing multiple projectors as theatrical lighting equipment is no easy task. Using a 10K projector as a light fixture allows for significant creative flexibility but that flexibility comes at a huge time penalty during programming. Projection mapping on complex organic scenic environments requires very sophisticated alignment and calibration software not typically available in off the shelf camera based auto-cal systems. 

I would respectfully disagree about the colorimetry of typical digital projectors as falling short of theatrical lighting equipment. There are families of both metal halide and xenon lamp technologies that have excellent color rendition. The problem is most classically trained lighting designers are unfamiliar with how these colors are created. And the programming workflow is unlike most lighting consoles and the traditional lighting design process. LED based DLP projectors will never allow for outputs above 4000 to 5000 lumens per projector. This is a known and accepted fact recognized by the manufacturers. It has to do with the physics of how the LED light is collected and the thermal management. This is why many manufacturers are experimenting with hybrid projectors that use laser diodes and phosphor coated wheels in conjunction with LED's. I would agree that the color from an LED projector is "unique" ! it is so spiky that it creates the illusion of high saturation and the CIE coordinates are way outside the video standards. And, unlike LED video screens, the manufacturers of LED projectors do not "bin" the LED's for color consistency from projector to projector. If you have ever tried to edge blend and color match an LED projector you know the problem.

I am excited that there are discussions about using projectors as lighting. It is a huge leap for classically trained lighting designers to adopt digitally based lighting. I am not talking about automated lights that have DLP engines. I am referring to the concept of lighting a show or performance the way you would with Ellipsoidals and Fresnels but using DLP based projectors. The creative latitude it gives the designer cannot be described. Classic 45, 45, 90 front back and sides. Just like a conventional lighting plot. When we do this, we start in layers. The first layer is the basic environmental look for a scene. This involves mapping the projectors to create seamless templates for each projector. This is where we add the textures, time of day, lighting direction etc. Then we add the VFX layer if a lighting effect is required, lightning, moving shadows, practicals etc. All of this can be done using multimedia server solutions like Pandora, Hippo, Watchout etc but the real bottleneck is the fact you cant work on a virtual canvas that shows you a single consolidated view instead of multiple projector views that have to be lit and programmed individually. 

Yes, the cost of this lighting rig is expensive but every year the cost goes down per lumen delivered. The cost of an installation grade 8000 lumen DLP projector is now comparable to a higher end mover with accessories once you add all the supporting infrastructure in. If you step down to 6000+ lumen Business class projectors with limited lens options, the cost per position is even better. But again, the programming is the challenge. 

This is a great forum and I hope this dialog continues. If any of you are doing theatrical lighting with projectors, I would like to chat

Tom LaDuke
Walt Disney Imagineering


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## tladuke (Apr 11, 2021)

So, this thread was in 2013 and it died here. I have now retired from Disney after 30+ years and I find it interesting that in all this time there has been very little theatrical lighting done using Digital video projectors as a replacement for conventional fixtures.

In the last eight years, projection technology has made stunning progress. 30K lumen DLP based laser and hybrid LED projectors are available from multiple suppliers. Digital workflow for multiple blended projectors is very well defined. Cost per lumen has dropped and contrast and color fidelity has hit amazing levels of performance. And, ETC has also delivered LED conventional fixtures with amazing performance. 

The vast majority of productions that use video projectors use them for projection mapping in the role of background or efx layers. It is rare to see the projector in the primary role of lighting. That's interesting. Why is that? Is it because of the Lighting designers and projection designers view their roles in completely different ways? Is it because the "quality" of video light is perceptually different? It is well known that even the best digital projector can't match the contrast level of a gobo. Is it a contrast issue? 

I'm just curious . Control Booth has great discussions and I would be happy to see a robust debate on this.


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## Les (Apr 11, 2021)

I think as mentioned back in 2013, it still gives a "stylized" effect. If that's what you're looking for, great! But it would never look natural. So much of lighting is also about angles, and having a projector (or even several) acting as primary lighting sources is unlikely to recreate the look of dozens (sometimes hundreds) of individually placed instruments. And as projector technology has gotten better, so has lighting lighting technology. While projectors could theoretically do the job, you would never get away from the fact that lighting instruments are better at it. Of course, this is not getting in to shadows cast by actors/scenery and the other technical challenges. Background layers and supplementary/special effects will always be where projectors excel - but I don't see them totally replacing a standard light plot.


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## jtweigandt (Apr 11, 2021)

If the source matured, the model I think would be cool is "virtual fixtures" Either built into the projector, or they live in an intermediate box with output to the projector. Just like the little magic sheet.. you hang fixtures with certain attributes, Aim them from the booth one by one, and Bobs your virtual uncle. Virtual fixtures could of course "shine through" one another. Address them with dmx, and you can mix projector/virtual with conventional down and side wash. A jump in tech, with less re training of current workforce, along with easier sales and marketing penetration. Dang I probably should have filed with the patent office before posting here. I am pretty sure that when I saw "Young Frankenstein" on broadway.. for the earthquake I was seated front row balcony.. and they had some big ass projectors projecting an image of the set onto itself.. then modulated to make the set "shake" Everything else was pretty dark at that point.. but I remember thinking "how are they shaking the set? dang" then I looked over the rail in front of me.


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## Lynnchesque (Apr 12, 2021)

Are there any projectors that can do a full out 0% black yet? 
I always thought a fully animated 'gobo' aerial beam effect would look pretty cool. But i'm under the impression that projectors can't achieve that contrast.


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## macsound (Apr 12, 2021)

Especially since you mentioned Disney I think of the castle at Disneyland.
Lately they've been doing tons of projection onto the castle itself but there's still strip lighting on the little edges of the balconies and overhangs on the castle. Using the combination of the projection and the lights on the castle create a far different and probably incomparable effect to projection alone. 

I also think of the shape of projectors.
High End did make the DL fixtures, which were moving light shape but all other projectors are enormous boxes with big fans. Even hanging one per lighting location would be so difficult because of the nature of the object.

I do think there's something in your idea though, why aren't there LCDs that can drop in a S4 gobo slot? Even if it was a circle approximately 800x600, it could be cool to have such variable control in a single fixture.


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## Les (Apr 12, 2021)

jtweigandt said:


> Dang I probably should have filed with the patent office before posting here.



Back in the early 2000's I was hanging out with some technical theatre friends and excitedly drew a concept I had come up with of an LCD projector on a moving yoke. Less than a year later, the DL1 was introduced 

Of course, none of my high school friends moonlighted at High End Systems - as far as I know


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## cbrandt (Apr 13, 2021)

macsound said:


> I do think there's something in your idea though, why aren't there LCDs that can drop in a S4 gobo slot? Even if it was a circle approximately 800x600, it could be cool to have such variable control in a single fixture.



I'm still waiting for this concept to come to fruition. It seems like the next logical step in gobos and beam control for standard fixtures. Even moreso now that we have color control at the light source with LEDs. There's a *lot* of light and heat coming through the gate on a S4. @Kelite can give you more info there, those guys are always working on new cool things. I'd imagine heat dissipation and longevity are what is keeping people from developing something there.

I think most designers would think it was a dream come true to be able to pick from 512 patterns in every ERS fixture to get just the right breakup or shape.


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## macsound (Apr 13, 2021)

LCD panels also suck up alot of light. 
Comparing a 150w HID source four's output to a dual 400w HID projector's output either means they need better reflector design or the panel, even when "open white" isn't allowing all of the light to pass through.
I've worked with and rented DLP projectors for events because I know they are more efficient but I'm one of those people who can always see the rainbow and it drives me nuts!


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## rieka (Jun 12, 2022)

Way back in 1994 I wrote a Letter to the Editor of TD&T suggesting that the future of lighting control & design lay in using open source protocols - tcp/ip, Ethernet cables instead of AMX/DMX, video projectors powerful enough to replace ellipsoidal spots & moving head projectors and so on. 

Some of this has come to pass. But the majority of stages in the world still rely on early to mid 20th century lighting technology - with one or two updates. Memory lighting consoles are now inexpensive enough to replace 2 scene presets in those installations fortunate to have SCR/triac dimmer banks (but what about installations with autotransformers?). Video projectors are now often used to reduce the need for practical scenery in school plays.

The enormous size of the installed base means that innovation and change come slowly. The Kliegl Bros. #70 plano-convex spot with a 1kw G40 bulb finally got replaced with a cast aluminum Century leko in the 1960s. Many buildings still have autotransformer controlled architectual lighting. Auditoriums with low utilization still find it cheaper to keep using incandescent fixtures like the Arial Davis/Electro Clntrols 3205 framing spot - which will eventually be replaced when the inventory of PAR64 bulbs dries up.


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