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Topic: Imax digital DCPs

Carsten Kurz
Film God

Posts: 4340
From: Cologne, NRW, Germany
Registered: Aug 2009

posted 12-13-2013 08:17 AM

Do you know if the image enhancer box is used for HFR, or bypassed?

- Carsten

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Stefan Vogels
Film Handler

Posts: 48
From: Aarle-Rixtel, Noord-Brabant, Netherlands
Registered: Jan 2010

posted 12-13-2013 03:51 PM

By-passed!

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Jonathan Goeldner
Phenomenal Film Handler

Posts: 1360
From: Washington, District of Columbia
Registered: Jun 2008

posted 12-14-2013 02:51 PM

quote: Tom Mundell
My understanding is AMC does use duel projectors in their ETX screens; I know at least the ETX at Tyson's Corner 16 uses duel projectors. The one (and only) time I was there getting the two images to overlap was a huge problem for some reason; the trailers were so blurry I complained, the projectionist stopped the trailers several times to try to realign the image. He got it much better than it started but it still wasn't very good. I'm not sure if this is a continuing issue (I have never returned to this theater due to this) or if this was ever a problem at other AMC's.

the double imaging flaw on the ETX screen at Tysons has been a continual problem since it's debut. Thankfully though both 'Frozen' and 'Thor: The Dark World' were flawless. Not if they could just recalibrate the sound levels so it wasn't so damn loud.

AMC also uses dual projectors over at the Uptown theater here in DC. Trailers have the flaw, but the features themselves look corrected - go figure why that is.

I cannot wait to see Seattle's Cinerama new Christie laser system come next year - in terms of brightness AND no doubling imaging. AMC seems so cheap in not thinking this would solve the occasional hiccups at both the Tyson's ETX and Uptown's systems.

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Marcel Birgelen
Film God

Posts: 3357
From: Maastricht, Limburg, Netherlands
Registered: Feb 2012

posted 12-14-2013 08:45 PM

Isn't the problem here that the trailers are in 2D and the feature is in 3D?

If both projectors are showing the same, not 100% aligned image without the polarizers applied, you will get a double image. In that case, it's probably a bad case of scripting, they should close the dowser of either one projector.

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Lyle Romer
Phenomenal Film Handler

Posts: 1400
From: Davie, FL, USA
Registered: May 2002

posted 12-14-2013 09:52 PM

Regarding AMC's ETX, I can only speak for the Downtown Disney 24 since it's the only one I've been in. That location is dual projector. They actually have the Real-D filters on a sliding rail system. For 2D, only 1 projector is used and the filter is out of the way. For 3D both projectors are used.

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John Thomas
Film Handler

Posts: 75
From: Boston, MA
Registered: Sep 2011

posted 12-15-2013 04:39 PM

The D-IMAX image enhancer also compensates for the darkened edges caused by the silver screen. Part of the morning calibration process involves red green and blue test patterns where you can see it brightening the edges (or darkening the center?) so the image reflecting back is more evenly lit. The image enhancer really is an impressive thing once you consider everything they're making it do. I could vent for days about the GUI on the SMS software however.

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Terry Lynn-Stevens
Phenomenal Film Handler

Posts: 1081
From: Toronto, Ontario, Canada
Registered: Dec 2012

posted 12-15-2013 04:47 PM

Hi John, is this morning test done everyday? Is it all automated?

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John Roddy
Expert Film Handler

Posts: 114
From: Spring, TX, United States
Registered: Dec 2012

posted 12-15-2013 06:07 PM

Calibration is done daily at startup (entirely automated). It involves several different image tests and audio adjustments. There is a camera hidden in the gap between the port windows, and at least three microphones scattered throughout the auditorium for this. Of course, in the event of a rushed startup or something, calibration can be bypassed and forced to load the previous day's info, but IMAX strongly recommends against this.

You can also go into the IE settings and force it to run part or all of the entire calibration at any point during the day.

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Terry Lynn-Stevens
Phenomenal Film Handler

Posts: 1081
From: Toronto, Ontario, Canada
Registered: Dec 2012

posted 12-15-2013 08:36 PM

Thanks John, I never knew IMAX projector self calibrated. If you don't mind me asking. How long does it take?

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John Roddy
Expert Film Handler

Posts: 114
From: Spring, TX, United States
Registered: Dec 2012

posted 12-15-2013 08:48 PM

Daily IMAX calibration takes about 40–45 minutes. About 30 minutes of that is spent just idling while it waits for the lamps to warm up. The actual calibration itself runs for maybe 10–15 minutes after that. The auditorium also needs to be clear during this time. All lights need to be shut off and doors closed as well, for the most accurate results (as recommended by IMAX).

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Marcel Birgelen
Film God

Posts: 3357
From: Maastricht, Limburg, Netherlands
Registered: Feb 2012

posted 12-16-2013 04:27 AM

I've never seen it in action, but if you take a look at the manual of Christie Duo (which also has been previously mentioned), it can potentially do anything that IMAX does in regards of dual projectors aligning on screen and it indeed does support both HFR and 4K.

It also uses a camera to check and calibrate the alignment. You can even program it to do an automatic calibration and log messages if stuff is not working out.

Besides the brand recognition, to me, this looks like yet another competitive advantage in regards to IMAX.

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Steve Guttag
We forgot the crackers Gromit!!!

Posts: 12814
From: Annapolis, MD
Registered: Dec 1999

posted 12-16-2013 06:09 AM

Christie Duo has the advantage that it gets the lenses VERY close to begin with...the potential downside is that it uses a mirror on one projector.

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Terry Lynn-Stevens
Phenomenal Film Handler

Posts: 1081
From: Toronto, Ontario, Canada
Registered: Dec 2012

posted 12-16-2013 09:03 AM

quote: Marcel Birgelen
I've never seen it in action, but if you take a look at the manual of Christie Duo (which also has been previously mentioned), it can potentially do anything that IMAX does in regards of dual projectors aligning on screen and it indeed does support both HFR and 4K.

Looks like a real PITA, Christie does not recommend side by side set up and RealD XL only works on the stacked set up which is recommended. Anyways, no theatre within 10 hours driving distance of me runs dual projectors aside from the IMAX locations.

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Steve Guttag
We forgot the crackers Gromit!!!

Posts: 12814
From: Annapolis, MD
Registered: Dec 1999

posted 12-16-2013 10:30 AM

When running the Christie Duo...you would not use an XL...you'd run just a polarization filter in front of each. Both projectors are active at all times.

As far as set up, I think Christie has it reasonably well thought out. There would be time aligning the mirror on the initial set up (the mirror is conformable to deal with curved screens even)...then the auto alignment system will take care of any lens variations. The demo I saw was quite good.

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Marcel Birgelen
Film God

Posts: 3357
From: Maastricht, Limburg, Netherlands
Registered: Feb 2012

posted 12-16-2013 12:33 PM

Page 52 of the manual accurately summarizes what works and what not.

Steve already said it, a normal RealD XL unit would be impractical in a normal dual 3D projector setup, since you would run Left and Right eye from a separate projector. There's a RealD XL-DP, which uses static polarizers instead of a ZScreen, but still offers the added brightness of the XL setup by inverting reflected light that get's reflected back from the polarizer. The problem with this setup is that it obviously doesn't fit in front of the mirror construction. The plate polarizer Christie offers also comes with a split-plate configuration that should fit in front of the single/dual mirror.

Christies plate polarizers are manually movable, but I didn't find any information what kind of polarization they use (linear like IMAX or circular like most of the rest).

It would be interesting to see the difference in convergence that can be achieved between the different setups (stacked, side-by-side, single/dual-mirror) that this Duo setup offers.

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