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Topic: Christie or Doremi IMB for Dolby 3D???

Arnold Chase
Film Handler

Posts: 41
From: West Hartford, CT United States
Registered: Nov 2013

posted 01-20-2014 12:12 PM

Once again I am interested in the collective wisdom of the folks here. I have a Christie 4230 with the Christie S2 IMB, along with a Dolby 3D system. At installation, I discovered to my dismay that there is no way to natively 3D color correct this configuration! Since I am not using a server (95% of my programming is alternative content from Blu-Ray or satellite), Dolby recommended that I get a Cine-Tal unit. Unfortunately, the Cine-Tal only has a SDI input and output, and the Christie SKA-3D processor that does the consumer to DCI conversion only has DVI-D outputs.

After doing some research on my own, given the cost of the Cine-Tal and the myriad of interface units needed, it would seem that by replacing the Christie IMB with a Doremi IMS1000 (which has native Dolby 3D support and a HDMI input), that would be a much simpler and cheaper solution. Am I missing something here?

Also, can anyone tell me if the Christie TPC can display the Doremi IMB menus (such as show control), as it does with the Christie IMB? In your experience, is there a downside to the IMS1000 versus using a separate SMS and IMB?

Thanks,

Arnold

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Steve Guttag
We forgot the crackers Gromit!!!

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

posted 01-20-2014 12:46 PM

First, no...the Christie TPC is only going to show the Christie IMB...that is their GUI.

The Doremi IMS uses a Web GUI.

That said...before you go spending a lot of money...you CAN color correct in the projector itself. The ICP has had that functionality for around a year and a half now.

What it is not going to do is balance the eyes but I have not found that getting precise eye balance to be all that critical and I have experimented with it.

So first, try color correcting each eye in the projector (you'll have to make two MCGD files for 3D, one for each eye and call those up on your channel preset).

Watch out on the new IMS or anyones IMB...I have not seen where they are providing for 3D color correction yet via the HDMI inputs.

As for the SKA-3D, yes it outputs on DVI but that would work with your projector...however, I don't think that the SKA-3D does internal color correction so you would be back to doing it in the projector itself.

I believe it would be possible to balance the eyes in the projector too but it would be much harder as one would need to set it up in something like a PCF file. I have not tried it but I think it is possible.

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Marcel Birgelen
Film God

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

posted 01-20-2014 03:16 PM

Besides pulling all kinds of single-stream 3D signals apart into two separate streams, doesn't the Doremi Dimension 3D box also support "per eye" color correction?

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Steve Guttag
We forgot the crackers Gromit!!!

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

posted 01-20-2014 03:52 PM

No. The Dimension 3D only separates the two images from a composite stream. The Dimension 3D isn't HDCP compliant either.

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Marcel Birgelen
Film God

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

posted 01-20-2014 04:24 PM

Yeah, you're right, there is no HDCP support in that box (and I guess those DVI splitters that "haphazardly" remove HDCP in the "splitting" process aren't totally DMCA compliant [Wink]

).

I do vaguely remember though, that there is support for color correction, but I'm not sure if this can be done per eye/channel.

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Arnold Chase
Film Handler

Posts: 41
From: West Hartford, CT United States
Registered: Nov 2013

posted 01-20-2014 11:47 PM

Steve,
Maybe I didn't make myself clear about the SKA-3D. I already have one, which is what I am using now - that's why there is a DVI-D to SDI issue preventing me from using the Cine-Tal. The tech that set up the projector did put in some sort of "approximate" color correction, I think using the method you described, but I am trying to achieve "screening room" accuracy. I thought the cost difference in getting a IMS1000 (after I sold the Christie IMB and SKA-3D) wouldn't be that much, but if what you're saying is correct about the color correction not being available via the HDMI input, then I might as well stay with what I have.
On a separate note, how well does the IMS1000's HDMI input work with the Christie? Does the projector internally convert the 8-bit color to 10 bits? (That's the good thing about the SKA-3D, despite its 'chunkiness' and temperamental HDCP)

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Steve Guttag
We forgot the crackers Gromit!!!

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

posted 01-21-2014 02:26 AM

Color correction in the projector is going to be as accurate as any...shoot the colors after you are done and you should be as accurate as for any movie.

DVI to SDI is relatively easily done (Black Magic Design or AJA make suitable converters) however it won't work for HDCP content like BluRays.

The CineTal is only good for non-HDCP sources. I'm pretty sure it will allow for eye balance on luminance.

As for bit-depth...from DVI it is going to be 8-bit on DCinema projectors with 3D since they all are doing single-link at the moment.

I think the trick for you is going to be getting the luminance equal for each eye, not color balance. I think it can be done but that will require another step to create a new TCGD for the bright eye to bring it down to the same level as the darker eye.

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Marco Giustini
Film God

Posts: 2713
From: Reading, UK
Registered: Nov 2007

posted 01-21-2014 06:25 AM

Steve,

If you mean dual colour calibration, I was told by Dolby that that is not the same colour calibration performed by a server. It made sense to me at the time, since Dolby 3D uses a different filtering than anything else. Never tried myself though and Dolby could be biased - they want to sell licenses.

Indeed, Panavision 3D was relying on that, completely ignoring the brightness.

I am not sure I agree with the eye brightness, even though it could be good enough.

I'll try myself next time I have some time to spare.

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Steve Guttag
We forgot the crackers Gromit!!!

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

posted 01-23-2014 06:38 AM

Who are they selling licenses to? Dolby 3D is a free license on all servers. The chief difference between doing it in the server versus in the projector is the eye-to-eye luminance balance. Dolby has claimed that they can get more light doing it in the server though I have not been able to verify that. I have done it in the projector on some of my early CAT745 installations when their software was not working properly (wrong color space) and the color correction was spot-on.

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