Monitor: multiple OS (Linux and XP), calibration, sRGB, internal LUT

Started Nov 28, 2007 | Discussions
Carl Robitaille New Member • Posts: 20
Monitor: multiple OS (Linux and XP), calibration, sRGB, internal LUT

Hi all,

My Sony G500 CRT just died on me yesterday. I had seen it coming, so I did some research on LCD panels a few months ago.

I was considering the NEC LCD2690WUXi-SV for many reasons:

  • 26"

  • Wide gamut

  • Internal 12 bits LUT

  • Good color accuracy

  • Came with the software and hardware to calibrate the monitor

At the time, I saw just one negative point that I could live with:

  • Refresh rate a bit slow for video and gaming.

Now that my monitor has died, I decided to look for new reviews and check for prices and availability in Canada. I was surprised to find in this forum (Thanks to everyone who wrote on the subject BTW! that the 2690 can't be calibrated in sRGB mode, only in Adobe RGB.... Say what?
http://forums.dpreview.com/forums/readflat.asp?forum=1004&message=25098312

http://forums.dpreview.com/forums/readflat.asp?forum=1004&message=25399659&q=2690+srgb&qf=m

http://forums.dpreview.com/forums/readflat.asp?forum=1004&message=25058538&q=2690+lut&qf=m

Now, as others have mentioned in these threads, I don't understand why the LUT can't be used to calibrate the sRGB mode if one chooses to. But it looks like Adobe RGB is just the preferred mode and NEC decided not to provide the sRGB calibration for a reason that eludes me.

I'm glad I found out before buying, but that said I think I would have liked that monitor. Now, does it really matter that you can't calibrate in sRGB? It depends on what tools you're using. I mostly work in Linux, and as some of you might know, color management is abysmal, or should I say nonexistent in Linux. My goal of having a LUT stored internally was in part to be able to calibrate the monitor in XP and then use the calibrated monitor in Linux.

The other issue is that most applications are not color management aware in XP either. Of course, photoshop is, and some will say that Firefox 3.0 will also be ICC aware, but really, I think sRGB is he to stay. Don't get me wrong, having the possibility to use Adobe RGB is a good thing, but I think I would be using the sRGB mode most of the time.

So, here I am, looking for a monitor with an Internal LUT of more than 8bits that can be calibrated in sRGB mode. Is there such a thing?

I could of course buy a NEC LCD2690WUXi-SV anyway, and use it in sRGB for the time being, hoping for Linux to get up to speed with color management and Adobe RGB. My question then.... is the color accuracy good in sRGB? Having a 8bit LUT on the computer is out of the question for me.

Carl

linuxworks Forum Pro • Posts: 18,937
Re: Monitor: multiple OS (Linux and XP), calibration, sRGB, internal LUT

its NOT non-existent. I've even seen some ways to import colorimeter generated profiles into linux! I never tried but I have seen links to write-ups where people have done it. the x-server can handle it, I think. I've seen gamma settings in x-servers for a long time, now.

what I do is to cheat, a little. I have xp do the monitor calibration/profiling and xp is my workstation (keyboard, mouse, screen). that all 'works' and my calibrator puck updates the profile in xp to keep things on tune.

then I vnc-connect to a unix box and since my i/o device (the screen and video card) are tuned as a set at the xp-level, you get that benefit when you 'graphics telnet' (if I may) to a vnc-server.

that means that when I run firefox on linux and 'send its display' over to the xp box via vnc, the images look perfect since the linux box and firefox (as an example of an app) are just sending the 'uncorrected' image data over the network and its at the final display stage (xp and its video card and display) that the profiling happens, or the rgb mappings happen.

not sure if that works for you. its a 2-box solution. but it works for me.

-- hide signature --
OP Carl Robitaille New Member • Posts: 20
Re: Monitor: multiple OS (Linux and XP), calibration, sRGB, internal LUT

Hi Bryan,

Thanks for the response.

linuxworks wrote:

its NOT non-existent. I've even seen some ways to import colorimeter
generated profiles into linux! I never tried but I have seen links
to write-ups where people have done it. the x-server can handle it,
I think. I've seen gamma settings in x-servers for a long time, now.

Well, maybe I should have left the color management in linux alone Like you, I've read about it, and to me it looks like it's not ready yet for prime time. Anyway, I'm not in a position to argue on that subject. I do hope that color management becomes easier in Linux in a not so distant future.

what I do is to cheat, a little. I have xp do the monitor
calibration/profiling and xp is my workstation (keyboard, mouse,
screen). that all 'works' and my calibrator puck updates the profile
in xp to keep things on tune.

then I vnc-connect to a unix box and since my i/o device (the screen
and video card) are tuned as a set at the xp-level, you get that
benefit when you 'graphics telnet' (if I may) to a vnc-server.

that means that when I run firefox on linux and 'send its display'
over to the xp box via vnc, the images look perfect since the linux
box and firefox (as an example of an app) are just sending the
'uncorrected' image data over the network and its at the final
display stage (xp and its video card and display) that the profiling
happens, or the rgb mappings happen.

I do that too.

But to come back to the issue of the NEC LCD2690WUXi-SV used in Adobe RGB, I think you would have to set your XP box (or application like Photoshop in XP) to use Adobe RGB before it gets transfered by vnc, otherwise the colors would be off (that is, if your x-server doesn't know it's working in Adobe RGB). I guess you could also risk applying a profile twice if both ends where using Adbobe RGB?

Anyway, like I said, I would be interested in using sRGB most of the time, so that using vnc with a basic configuration x-server would work fine, as it did with my now dead Sony G500.

OP Carl Robitaille New Member • Posts: 20
Re: Monitor: multiple OS (Linux and XP), calibration, sRGB, internal LUT

Carl Robitaille wrote:

I could of course buy a NEC LCD2690WUXi-SV anyway, and use it in sRGB
for the time being, hoping for Linux to get up to speed with color
management and Adobe RGB. My question then.... is the color accuracy
good in sRGB?

Well, I found the answer in another thread: No, it's not accurate.

UCSB wrote:
( http://forums.dpreview.com/forums/read.asp?forum=1004&message=25238661 )

Also, I can now answer the question that I asked above about sRGB
mode on the 2690. sRGB mode does not seem to be very good. When I
switched it on the color did not seem to be extremely accurate. You
can't calibrate sRGB mode using SpectraView II ... so I used Eye-One
Match3 to do an external calibration while in sRGB mode. I ended up
with a DeltaE in the Match3 monitor validator of 3.4. This confirmed
my impressions. I'm not entirely sure about my approach. But,
basically I do not feel that you can rely on sRGB mode for accurate
color. I dropped the sRGB project once I realized that I was getting
a good solution with the next generation of Foxfire.

OP Carl Robitaille New Member • Posts: 20
Re: Monitor: multiple OS (Linux and XP), calibration, sRGB, internal LUT

Carl Robitaille wrote:

So, here I am, looking for a monitor with an Internal LUT of more
than 8bits that can be calibrated in sRGB mode. Is there such a thing?

I got my answer in another thread, where I should have posted my initial question in.... sorry about that:
http://forums.dpreview.com/forums/read.asp?forum=1004&message=25814602

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