Film-Tech Forum ARCHIVE: NEC NC900C GDC IMB HDMI In

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Posted by Paul Looker (Member # 5420) on 02-20-2014, 09:22 PM:

I'm trying to run a blu ray player but the image is very red. Any ideas?

Posted by Mark Gulbrandsen (Member # 72) on 02-20-2014, 09:40 PM:

You're in the wrong color space for HDMI.

Posted by Paul Looker (Member # 5420) on 02-20-2014, 09:40 PM:

Would anyone know how to change it?

Posted by Ian Freer (Member # 1940) on 02-20-2014, 09:47 PM:

Hi Paul

The colour space is possibly incorrect. What Title (or preset, channel, whatever you call it) have you selected on the projector?

If colour space is the issue, there should be two ways to resolve this with this combination of equipment:

Option #1: Set up a Title in the NEC that uses the IMB as the input, but uses the 'DVI 2048x1080' PCF rather than the PCF used for DCP playback (i.e. 'DCDM_XYZ_185').
Select the appropriate Lens, Lamp and Screen files, save and assign this title to a new Preset Button, and select this to play BD.
(Obviously DCP's will now look incorrect in this new Title...)

Alternatively, if you have a recent software version;
Option #2: The GDC can do a colour space conversion on the fly enabling you to utilise the existing Titles and Preset Buttons already configured for DCP.
From the Configuration menu, select Alternative Inputs. Go to the Preset tab. Here you change the output color to XYZ rather than RGB as it will be by default. (You can either modify the Default preset or create a new Preset depending on your needs).

I had a quick look a couple of days ago using a mediocre quality DVD through a mediocre BD player. In my very short assessment, using option #1 looked better.
I plan on having a more in-depth look, with some better source material at some point, but it's not on the top of my priority list unfortunately....

Hope that helps.

Cheers,

Posted by Paul Looker (Member # 5420) on 02-20-2014, 10:29 PM:

Is there a default configuration password?

Posted by Carsten Kurz (Member # 5396) on 02-21-2014, 05:41 AM:

The installer should have set this up for you. In the long run, you should be able to do jobs like this on your own, so I suggest you get some training. Do you have the manuals for the IMB? You should also find the passwords with the documentation.

As a short cut - you may find colorspace settings in the BluRay Player as well - go through them, maybe one of them fits the current setting of the IMB. However, if it's set to xyz, you're out of luck, you won't find a BluRay Player with that setting.

- Carsten

Posted by Steve Guttag (Member # 268) on 02-21-2014, 06:37 AM:

Ultimately, the BluRay wants to be in the REC709 colorspace. The intense red/pink shade tells me you are in the XYZ colorspace on something that is coming over as RGB. In the NEC title, set up a REC709 color space (I don't recall if it comes with one by default that is called that...the DVI ones are in REC709). If you end up using a DVI one as your template...you'll have to change the input to the IMB. Don't forget to save it as a different PCF with a name that will make sense.

Posted by Barry Floyd (Member # 385) on 05-05-2014, 11:16 PM:

I've got the same issue with a GDC IMB and a Barco DP2K-23B. Everything I play on the BluRay, everyone looks like they've been in the tanning beds way too long. I've logged into the projector via the Barco communicator software and tried different color space files withing the PCF files. It was set up by the installer to use REC709, but the reds are way overblown, and the picture just looks way too dark. I've tried different color space files, and nothing seems to fix the issue. I've tried DCDM_XYZ, DCDM_RGB, and even one for HDTV.
It's like I need to adjust both the brightness and contrast if there was such a setting.

Posted by Carsten Kurz (Member # 5396) on 05-06-2014, 04:02 AM:

Also check the BluRay Player output setting. It has to match the setting in the projector.
If you don't find a suitable setting there for a REC709 in the projector/IMB, then something else is screwed up.

- Carsten

Posted by Barry Floyd (Member # 385) on 05-06-2014, 10:48 AM:

Would I get any different results if I went through the DVI inputs on the Cinema Controller card? I know I'd have to edit my macros to use the DVI input as opposed to the Media Block HDMI port, but other than that would it hurt to try?

Posted by Steve Guttag (Member # 268) on 05-06-2014, 09:22 PM:

Having "intense" or "subdued" colors when using an IMB almost always indicates that the color space on the projector is wrong...most of the time an IMB's input is wanting to use the DCDM RGB color space for HDMI sources as opposed to DCDM XYZ for DCinema.

That said, some IMBs can do the color space conversion.

Typically when one is in a REC709 versus a DCI color space, you will get wrong colors (intense Pink or Green). There are also the RGB vs YCrCb to make sure are correct too...they will get you the unwatchable picture stuff too.

Posted by Guillermo Conde (Member # 3176) on 05-07-2014, 10:39 PM:

use the AUTOMATIC preset macro, it will correct the color (usually on #3 preset button)

Posted by Barry Floyd (Member # 385) on 05-08-2014, 11:38 AM:

I spoke with GDC technical support this morning, and when I described what was happening, the tech immediately said - firmware update. The new SMS version 9.0 Build 271 allows the HDMI port on the IMB to use the same macros on the projector for flat and scope as our regular DCP movies. He sent me the new firmware and I'll update it tonight and see if it makes a difference. He said it would probably clear things right up.