# Linking Projectors



## jlw6e (Jan 24, 2013)

I am doing the musical Alice in Wonderland and want to just use projectors to create the Wonderland and other stuff (I don't want to build anything, except for flats with white sheets on them or whatever works best). Show is in May and I want to be able to run three to four projectors from one or two computers. The deal is that I want to be able to run different images from my computer. So lets say I have two projectors running from one computer, one projector stage left and the other stage right. The image on stage left will be slightly different from the image of stage right. Any thoughts? Thanks!

Jordan


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## Morte615 (Jan 24, 2013)

You can do this from QLab if you get a powerful enough computer that has multiple video outputs. Last summer we had 4 projectors and the computer monitor running all at the same time with different images. Though we did notice that at times the computer would lock up and then unlock and whatever was on the screen would just disappear until the next image was sent. This was really noticeable only during one scene but I still think it was a matter of settings on the computer and not anything to do with the hardware (though they wouldn't let me near the computer, to afraid of something happening to the "show" computer. Can't blame them about that but I did come from the computer world before entering theater so I do know my way around a computer)

I would probably say that 4 projectors would be my limit though to use with QLab, any more than that and I would look at a media server that would allow you to have more inputs and outputs. And a media server is built to handle multiple High Definition video sources.


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## Grog12 (Jan 24, 2013)

I've done this successfully using Keynote and digital zoom on high end projectors.


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## dbaxter (Jan 24, 2013)

Unless you are using a strong computer (I5 or greater) and a more powerful video card than I know about, I would be suspect driving more than 2 projectors plus the main monitor with one computer. You will probably need to network in a second computer to do the four images. We drove 6 separate images for our production of Tommy. Here is a uTube link. Disclosure - we were using Cue Player software and three computers. You may PM me for more details.


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## ruinexplorer (Jan 25, 2013)

Do you already have some of the equipment or do you still need to acquire it? Do you have a budget in mind for this project? I am assuming that it will be rather low since you are using basic flats instead of screens.

In general, a desktop will be better than a laptop. Qlab is a good option for control since it has a rather inexpensive rental option, but it requires that you use Mac computers.


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## Brandofhawk (Jan 25, 2013)

My thoughts on projections:
Projections seem like it could be a very cheap way to do things, but there is a lot of headache involved so you have to weigh the pain/trouble/time against the cheapness of doing it. Especially if it is your only scenic element, because what happens when the projections go down? (Depending on the stability of the system, it can happen all the time or never). Make sure you think through projections well before your tech. (And it seems you are!  , but this is just the tip of the iceberg). If it is your first time doing projection for theatrical purposes, than I suggest you start working on the system now to try and head off any potential problems. 

Determine what you may need/want the projections to do, so you can figure out how to make it do all those things. 
Do you want video playing in the background?
Do you want static images?
Do you want a combination?
How does the different Media shift between the two?
Is it a hit play at the beginning? Or do you need cues to change on cue? 
And many more...

Each of these questions opens and closes options to what the system you need to build.



My advice is look into systems where you can control what is being displayed and when. Hippotizer and Watchout and Qlab (professional license) are three programs which I personally know of for displaying on multiple screens with advanced capabilities. Powerpoint would let you control one screen from one computer with limited control. 


So In college we used Dataton's Watchout system. It works pretty good, but to be able to use it can be pretty expensive (to buy). 

Dataton | www.dataton.com
Green Hippo - The worlds best solution for realtime video playback on events worldwide
Figure 53 | QLab | Live Show Control for Mac OS X

Good news is, you can rent it from companies and they may have technicians to send out or call if you don't know what is going on and it may better fit your budgets. Look on their website, and you can find a list of places to buy / rent it.

I don't mean to sound discouraging or anything of the sort. I'm just trying to start you thinking about all the variables for your production to have as little headache as possible. It probably also sounds very negative because I am currently working on a production where 3 days before opening they came and said "so we want to do projections" and didn't think about how to control the media to look seamless on the projector... resulting in this late night, the night before opening. I would personally love it if you did this and then showed us some images of the production, because projected media is the newest kid in town (stealing lighting's thunder). 

As for placement of the projectors, there are a lot of options. You can rear project, or front project. You can mount them on their sides to make a portrait or keep them straight on to make them landscape. you can mount them from the ceiling, or place them on the floor. You also will need to figure out which projectors you are using and their throw distances and how bright they are going to be when you have stage light on your actors bouncing back onto those white walls. Projection Calculator Pro - Projector to Screen Distance This website will let you know the answer to some of those questions.

I also will offer up my advice and help as far as I can give it with my knowledge of projections and my ridiculous questions of abstractness / troubleshooting. 

So you know where I am coming from, I have worked with computers my entire life, and have been working with projections in theater at school for the past 3 years. I've worked on productions varying from 1 projector running powerpoint, to a 6 projector, 6 live feed cameras, traveling via Ethernet across two different spaces (3 live vid from one space, and 3 live vid back. Sound also sent between the two... it was quite a headache).


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