Film-Tech Forum ARCHIVE: imax christie projectors

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Posted by George Murray (Member # 6991) on 03-19-2013, 06:43 PM:

Hi i was just wandering if anyone knew the deal with the imax christie projecors? Are they customized projectors solely sold to imax or are they standard 2k christie machines just wrapped in an imax shell

Posted by John Roddy (Member # 7348) on 03-19-2013, 07:20 PM:

We have those at my site. I haven't actually seen the same projector in a non-IMAX environment (we use Barco projectors in all of our other auditoriums), but as far as I can tell, it's a standard Christie projector with a few IMAX mods. I doubt you could take it out of an IMAX setup and use it in a regular cinema environment though. I imagine it's the same case with the newer Barco-powered IMAX system.

Is there any particular reason why you're wondering about it?

Posted by Dave Macaulay (Member # 813) on 03-21-2013, 07:25 AM:

The Christie ones are standard projectors, Imax removes the outer covers but that's pretty much it for mechanical mods. The software is different though, Imax runs the lamps at 100% and uses the Z axis lamp motor to adjust light level.
Pretty much the same for the Barco Imax systems, there's essentially a standard 32B projector without the outside covers hidden under the Imax covers. These are the only Barcos I've ever seen with the optional motorized lamphouses.
The image data path is rather different, that's the main Imax "trick" that differentiates them from other dual projector setups. The system calibrates itself every day, there's a "black box" that aligns the images from the two projectors by manipulating the image data. That's also why inside the entire outer cover is a "secure area", the image data has to be decrypted before the black box so the usual D-Cinema security model with no decrypted image data anywhere except at the light engine devices isn't possible.

Posted by Jean-Marc Toussaint (Member # 4784) on 03-21-2013, 04:17 PM:

Are your Digimax Theaters only showing Imax films in the US? The Imax Theater in Paris where I used to work was sometimes showing non-Imax films.
And yes, they are regular Christie projectors in big boxes. Servers are Doremi, all controlled by a console running Windows XP.The dowser/polarized filter system is a pair of flimsy looking motorized devices on tracks attached to the front of the lenses that are being kept cool (and supposedly dust-free) by a small rack of computer fans.

Posted by John Roddy (Member # 7348) on 03-21-2013, 04:41 PM:

There were some occasions where the IMAX films coming out were scarce and not that great. At those points, we did load non-IMAX features and run those. The only catch is that the system automatically adds in a special tag right before the feature to make it absolutely clear that the feature is not an IMAX experience.

I'd also like to note that our system initially had trouble playing non-IMAX content because it would always run the descriptive audio tracks without giving us any way to stop it. But we were able to call IMAX and have their techs fix it via remote assistance. No trouble since then. Of course, IMAX movies are a lot more common these days, so we don't really run anything else anymore.

Posted by Jean-Marc Toussaint (Member # 4784) on 03-21-2013, 06:10 PM:

Yes, we had this tag too. But the dual projector system was nice for screening 3D movies (we ran Ice Age 4 last summer prior to the release of Dark Knight).
The weirdest thing that ever happened to us was during the test screening of the last Pirates of the Carribean movie. I can't remember what went wrong (the Imax system can be quite temperamental) but we ended up with a green and red image. As the only english-speaking member of the staff, I had a ball calling the Imax Hotline in Canada asking why they had sent us the anaglyphic version of the film. The person on the phone had no clue of what anaglyphic was. Problem was fixed the next day.

Posted by John Roddy (Member # 7348) on 03-21-2013, 08:12 PM:

It's the freakin' daily calibration. The IE is really not that reliable. I had an issue a few weeks ago where it pushed the SCOPE image from Top Gun 3D all the way to the very top of the screen and distorted the picture near the bottom. I had to wait until the show ended to perform another part of the calibration to fix it.