# Moving backdrop projections?



## sdrival (Mar 3, 2012)

Does anyone know what equipment was used to create the moving backdrop/projection effects in You're a Good Man, Charlie Brown on Broadway? The video below is an example of a simple fade effect, but I remember the images could move too. I'm looking to create a similar effect, but I know very little about projections. Is it just a video projector set up behind the scrim or was it an actual video screen? Is there a good place to rent this equipment and find out more information about it? 


http://youtu.be/2ix8TfqtNis?t=3m37s


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## 65535 (Mar 3, 2012)

Probably a rear projection screen and a very powerful projector 20k-30k would be common for such an application. The projectors themselves run in the $100k+ range but you should be able to find a rental company that will rent them for a pretty penny.


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## Esoteric (Mar 4, 2012)

65535 said:


> Probably a rear projection screen and a very powerful projector 20k-30k would be common for such an application. The projectors themselves run in the $100k+ range but you should be able to find a rental company that will rent them for a pretty penny.



We do that stuff all the time with 2-3 3000 linen projectors that run $1700 or so each. That size screen would probably cost $15k total (that is a large screen).

Mike


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## sdrival (Mar 5, 2012)

Esoteric said:


> We do that stuff all the time with 2-3 3000 linen projectors that run $1700 or so each. That size screen would probably cost $15k total (that is a large screen). Mike


 I would definitely need one much smaller than the example in the video. Our stage isn't that big. I'm just looking to create a similar effect with a backdrop that we can project moving images on. Is there a minimum amount of space required for a rear projector between the projector and the screen?


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## metti (Mar 5, 2012)

sdrival said:


> Is there a minimum amount of space required for a rear projector between the projector and the screen?



Yes. You can calculate that based on the lens you will be using and the size of the screen you want. If there is insufficient space it is possible to project upstage and have that reflected off of a first surface mirror and back onto the RP screen but that can be tricky to align and will require a comparatively brighter projector since it is a less optically efficient setup.

Really though, if you are going to have a projected backdrop, you are going to need content to project and that will require a projections designer and they will be the one to help you figure out what the hardware end of things should look like.


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## metti (Mar 5, 2012)

Esoteric said:


> We do that stuff all the time with 2-3 3000 linen projectors that run $1700 or so each. That size screen would probably cost $15k total (that is a large screen).



While it is completely possible to fill a screen like that with a handful of 3ks or even one 3k, there is no way that you could do what they are doing with projectors that dim given the extremely high levels of ambient light in that clip. Even 5ks would be totally washed out beyond recognition. For an RP screen of that size with the stage light levels at what they appear to be, I would be specing a couple 20ks or several 10ks for that screen because anything less would lose all color and visibility. I'm skeptical that 2-3 3000 lumen projectors would even be able to be seen by the audience at all if they were used with the screen and light levels displayed in the video.


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## museav (Mar 5, 2012)

The image in that clip seems to show a seam and two hot spots, so probably a couple of edge blended projectors. Larger productions may use high density LED walls rather than rear projection as those make it much easier to get a large image with high brightness that won't be washed out by stage lighting.

How well you can control and limit the lighting hitting the screen is potentially a critical factor. How well people need to be able to discern the content is also a factor, obtaining a realistic look or legible text may be a much different situation than creating a suggestion of a mood or setting. That somewhat goes to metti's point of knowing the content and intent in order to be able to determine the appropriate hardware.


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## Esoteric (Mar 5, 2012)

Interestingly enough I have done projects with 10k lumen projectors (4 or more at a time) and with 3k lumen projections. It does all depend on what you are projecting and your control of ambient light. Of course in a theatrical setting controlling ambient light is much easier than in my church projection world (where the only front light is often PARcans from a very low angle). 

Just to give you some background on projection. We use a measurement called ftL (foot lamberts, basically lumens per square foot). Movie theater screens are often 10-14 ftL. This is because they are in completely dark rooms. When we do church projections in high ambient light areas (direct sunlight with readings of 150+ FC at the screen) we recommend 75-100 ftL. A 3000 lumen projection over a 9x12 surface (which is a very common measurement) is 27 ftL.

27 ftL is very bright. You can see a lot of detail, and get enough to make it show up. Also, if you watch the lighting work on that video the lights are cut very well to the botto of the projection surface. If you shine a light directly on to any backdrop you are going to wash it out (one reason I hate it when people use FOH spotlights with a cyc when the actors run upstage and interact with it), I dont care if you are using a 3000 lumen projector or a 10000 lumen projector.

Now, in our rental inventory are two 3000 lumen projectors that we often do 9'x24' images with. I will post some pics below or you can go look on Esoteric Visions.

These are also super short throw. That means my 9'x24' image is created with the projector less than 4' from the screen. Now, I have to burn 3' at the top or bottom of the screen (depending on how the projectors are hung), but that is a small price to pay.

Now, as always, the more lumens the better (usually), and things vary by performance, but needing a half dozen 10k projectors to make a nice background image is just siply untrue.

As far as content, there are thousands of sites on the internet you can license still or moving content from, or if you are feeling creative, by some video editing software and make your own.

Let me know if you have any questions. All the projections are done with 2 3000 lumen projectors. One of the photos is much larger than 9'x24' but the others are 9'x'24.

Now of course Les Mis had 4 multi thousand lumen projectors for a comparatively small image. But you don't HAVE to do that.

Mike


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## Esoteric (Mar 5, 2012)

I saw the twin hotspots too.

Also something I have learned from being a photographer as well as a designer is that it is difficult to discern screen size from those shots. In some the screen appears to be 20' tall and in others only 8' tall. Perspective is everything in photography.

I am guessing two edge blended 8k or 10k projectors (since it is Broadway). Whatever the local rental house had laying around the warehouse.

Mike


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## SHARYNF (Mar 8, 2012)

Hi Mike
what make/model 3k short throw projectors are you using?
Sharyn


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## Esoteric (Mar 9, 2012)

SHARYNF said:


> Hi Mike
> what make/model 3k short throw projectors are you using?
> Sharyn



I use the Dukane 8103H.

Mike


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## Esoteric (Mar 14, 2012)

Okay, here is a projection on a church brick wall. The wall is appx 91' in width and 21' tall (give or take). These photos are with 2 2000 lumen Sharp Notevision PG-C45X projectors from appx 65' away on a balcony through glass. The first photo is in the dark. The second is with 14 Source4 PAR 750W units with R74 gel. The third is with the PARs plus 40 Source4 26 degree 750W ERS units. Camera settings remain the same throughout.

Mike


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