Luminous Landscape Forum

Raw & Post Processing, Printing => Colour Management => Topic started by: Geraldo Garcia on January 07, 2012, 03:03:51 pm

Title: Lower red saturation after calibration and profiling
Post by: Geraldo Garcia on January 07, 2012, 03:03:51 pm
Hello friends,

I hope you can help me with a weird problem I am having for a few months. I am no newbie on colour management but this problem exceeds my knowledge (and patience).
I have a printing studio and two computers dedicated to image edition and printing hooked on HP Z3200 printers. Everything works fine, I make my custom profiles, my monitors are regularly calibrated and profiled and everything works as supposed to. Everything but one monitor.

The monitor in question is a LaCie 724 24" (wide gamut) hooked on a computer running windows Vista Ultimate 64 bits. The monitor is excellent, but after calibrated and profiled it displays the reds somehow at a lower saturation.

When I print, the reds are saturated as they should be. When I move the image to my other monitor (Dell U2410, also wide gamut, calibrated and profiled with the same hardware and software) the reds are displayed saturated as they should. And the most weird detail: When I DISABLE colour management the reds are displayed properly saturated on the monitor in question, so the monitor is capable of displaying them. The other colours are as perfect as possible, only the reds have this issue.

I calibrated and profiled it with a lot of hardwares (i1 Display 2, i1 pro, Colormunky photo) with their proprietary softwares and also with LaCie Blue Eye Pro and Argyll softwares. Always the same.

Any Ideas?

Thanks in advance.
Title: Re: Lower red saturation after calibration and profiling
Post by: howardm on January 07, 2012, 04:04:06 pm
I might start looking at how well the 'pucks' are sealed against ambient room light during the calibrating process.
Do you lean the display back so the pucks are resting on the screen?  If it's too much, you may be distorting the
area right under the puck.  If so, make the screen as vertical as possible while maintaining good device/screen contact.

Maybe throw a black Tshirt over the puck to block ambient?  Is the screen warmed up 30-60 minutes (ditto on each puck)
prior to calibration?
Title: Re: Lower red saturation after calibration and profiling
Post by: Geraldo Garcia on January 07, 2012, 04:26:23 pm
Hello Howard,

Thanks for your answer.
Unfortunately I already did everything you said.
My monitors are equipped with hoods and I tried with the room lights on and off. I do indeed lean the panel a bit, but just a bit and it does not seem to be enough to generate any pressure. I always wait at least an hour after turning the monitors on to calibrate and profile. Anyway, the same procedures works fine with the three other monitors I have on the same room.
As far as I can think it is not a computer problem as the other monitor works fine.
It is not a colorimeter/spectro problem as I tested various and they do a nice work on the other monitors.
It is not a monitor limitation to not display the saturated reds properly because it displays very saturated reds without the profile.
Looks like the problem is on the profile, as if the profiling hardware/software was unable to recognize correctly the reds the monitor can display... but only on this monitor.

I have no clue.

Thanks again.
Title: Re: Lower red saturation after calibration and profiling
Post by: Geraldo Garcia on January 08, 2012, 03:02:16 pm
I was thinking a bit more about this problem and an idea came to my mind:

Is it possible to manually edit a monitor profile? If yes, what software should I use?
I do understand that it goes against the logic of using specialized hardware and software, but I would like to "pump up" the reds just to see if it makes any difference.

Thanks.
Title: Re: Lower red saturation after calibration and profiling
Post by: digitaldog on January 08, 2012, 03:16:26 pm
Is it possible to manually edit a monitor profile? If yes, what software should I use?

No. It reflects the current calibration so that’s not going to work and would be awfully time consuming until your next calibration invalidates the profile.

You can and should edit the calibration targets to produce the visual results you desire and the profile is then built upon those settings. See:http://www.luminous-landscape.com/tutorials/why_are_my_prints_too_dark.shtml
Title: Re: Lower red saturation after calibration and profiling
Post by: howardm on January 08, 2012, 03:52:36 pm
Leaving aside the 'should you' question and the points that Andrew brings up, I will say that BasICColor Display 4/5 software *does* allow you to modify the RGB curves of profile.  But that doesn't answer this particular riddle.
Title: Re: Lower red saturation after calibration and profiling
Post by: Geraldo Garcia on January 09, 2012, 07:54:11 pm
Thanks Howard,
Good to know that. I don´t think I will go through that route but is good to know that it is somehow possible, even if is just for testing.

Andrew,
Thank you very much for jumping in. Your texts always help me.

I spent almost the whole day today over that monitor. I calibrated and profiled it a dozen times changing various settings like drift compensation, black point correction, calibration and profile quality, type (LUT or  matrix) and editing the testcharts (to ad various patches of different saturated reds). No progress.

The saturated reds are still a bit orange and undersaturated if the profile is active. If I turn off the profile on the O.S. the reds turn to be very saturated (as usual on wide gamut displays).

Any ideas on why that happen on that monitor and not on the other 24" I have on the same computer? Any hints on how to create more effective testcharts?

Thanks again!