The Image Mill Part II-Projection and Lighting

This is Part II of a series; Part I is here.

In the Image Mill, video and lighting are merged in really beautiful ways. In fact, the first time I saw the show, I didn't even realize that a few of the lighting effects were not part of the video image. Steve Blanchet is credited as "Coïdéateur et coconcepteur des images" (I couldn't find a good translation on this, but I think it's image co-imaginer and co-designer), and the Lighting Designer is Martin Gagnon.

27 Christie Roadster S+20K DLP™ 20,000 lumen projectors (standing on end) are used to cover the massive projection surface, with most covering a block of four of the eighty-one silos. 

The images themselves are played back using E\T\C Audiovisuel's OnlyviewTM software.  Note that this is not ETC the American lighting company, it's E\T\C Audiovisuel, a French company you may remember as the creator of the Pigi large format film projectors (in fact, they use one Pigi on the Image Mill to project credits), and also the creator of a sprocketed scrolling system that allowed sophisticated moving matte film-based images (I used to work for Production Arts Lighting, which distributed Pigi and Pani projectors).

Onlyview, like Dataton's Watchout  uses a master control computer, and then one computer for each display.  All the machines are networked together using Ethernet, and then the DVI video outputs of the display machines are converted to fiber to cover the massive site.  One fiber run, in fact, back to the main control room on the other side of the lake, is 2km (more than a mile) long!  All the machines are housed in a climate-controlled control trailer located near the base of the massive mill (it was located here to minimize the fiber runs out to the projectors).  Here's my thumb showing the resolution of one pixel projected on one of the silos:

While the power load of the massive show is trivial by the standards of a grain mill, much care had to be taken in devising the system, and each video projector is given power exclusively from a single point, technical grounding system.  All the power was run in overhead pole-based lines installed by a specialty contractor.

The lighting system is run using a GrandMA located on the other side (where the audience is) of the Bassin Louise (marina basin)  from the mill. The console connects over fiber-based Ethernet to 9 MA Lighting NSP processors, each of which can process four universes of DMX.  So that would be about 18,432 (corrected 7/8/08) DMX channels, and they need all of them because they are addressing 208 LED lighting fixtures, many on a pixel-by-pixel basis for some of the effects.  The LED fixtures were selected primarily due to heat issues, with strict limits imposed by the mill due to the risk of a dust explosion.  Each of the silos included in the show gets an Italian moving LED fixture which is overhung off a counterweighted pipe structure, and a strip-based LED fixture which can create vertical lines on top of the silos.  To support all this a massive 500' long truss structure was installed on the top of the mill using a crane (Mario told us at times his crew exceeded 100 during load in).  Lighting load in took about two weeks, and even simple maintenance can go slowly due to the way the fall arrest lines are laid out across the massive building.

Click here for Part III of this report.