Checking monitor calibration

[skid00skid00]

I found that using a Solux lamp enabled me to calibrate my DSLR, and also works great for verifying your CRT calibration.

I used this pic to check my calibration.  Process your image twice, once with WB on the CRT gray patch, once on the print patch.  Crop out the print in each image, stretch any which is not rectangular to make comparison easier, and eyeball them.

I found that my 6500K crt WB at 6600K, and my Solux (which measures 4175K with an EyeOne Pro spectro) Wb at 5250K  (both in ACR).  There are very slight differences in just a couple patches.

[pobrien3]

When I was first using two ACD monitors, I was reasonably happy with the calibration I got from the Monaco Optix Pro software.  I never got perfect match to my prints, but then I had a low-grade printer so I didn't expect a lot more.  Later, I upgraded the printer and Mr Rodney made me an excellent profile, which enabled me to see that my monitor calibration was off.  I bought BasICColor which gave me profiles that were a far better match to the print, and I finally had excellent monitor to print matching.

I replaced a dead ACD with the Eizo CE210W which meant I also had to replace my video card, so all was sent back to square one.  Initially I calibrated the Eizo with it's own software, and it looked fine to me, but the ACD looked quite different - just a matter of re-doing the Apple, I thought.  In the meantime I hadn't used the monitor for photos, I've just been working at my day job.  When I finally got round to evaluating it properly, I could see that my initial non-critical impression was quite far off.  The ACD was actually still pretty good using its old profile, but the Eizo was not good.

I've since manually adjusted the profile from within the BasICColor software and it now is a closer match, but not good enough.  I'm struggling to know where I go from here.

BTW, I examine my prints under controlled 6500k lighting

[RedRebel]

The gradient looks smooth, but not neutral - there is a pronounced magenta cast.

The BasICColor software takes account of the ability of the monitor to be hardware calibrated, and offers the option for Hardware Calibration (monitor LUTs), which I selected.  I don't know how to check if there is a monitor profile active as well as a video card profile - I don't think so, but I'll do a bit more reading - the Eizo documentation is crap.

Cheers,
Peter
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Is there a way to return to the factory defaults, to see if the magenta cast dissapears? This way you can rule out if the color cast is caused by the calibration proces or not. I couldn't find any usfull info on this subject on the Eizo website or in the documentation (I downloaded the Colournavigator CE software).

[pobrien3]

René, I tried your advice by removing all profiles associated with the monitor, but it just seems to have retained the last profile.  I'll dig into it a little more to see if there's some way I can do that, thanks for helping!

Peter

[RedRebel]

It's a pitty that until now, no one with real life experience in hardware calibratable monitors has responded yet. When using a hardware calibratable monitor like the Eizo CE210/240, CGxxx and the NEC's 2190UXi (spectraview) etc... the monitors internal LUT is adjusted while the graphicsboard LUT remains linear (neutral). But I don't know if the Eizo software, after calibrating the monitor automatically resets the graphicscard LUT and updates the profile (WIn2000 > Controlpanel->Display->Color management->Default Monitor profile).

I hope you can find the problem..  ..good luck.

[eronald]

It's a pitty that until now, no one with real life experience in hardware calibratable monitors has responded yet. When using a hardware calibratable monitor like the Eizo CE210/240, CGxxx and the NEC's 2190UXi (spectraview) etc... the monitors internal LUT is adjusted while the graphicsboard LUT remains linear (neutral). But I don't know if the Eizo software, after calibrating the monitor automatically resets the graphicscard LUT and updates the profile (WIn2000 > Controlpanel->Display->Color management->Default Monitor profile).

I hope you can find the problem..  ..good luck.
[a href=\"index.php?act=findpost&pid=84799\"][{POST_SNAPBACK}][/a]

Actually, I own a CG210 which has the writable hardware LUTs and DDC ability; I also have a cheap but decent Samsung monitor attached to the same Mac, and matched calibrations. I believe I am reasonably familiar with the issues involved, although I avoid using PCs.

If an Eizo failed to calibrate, I think

-  I would first get rid of the other monitor, turning it off and disconnecting it from the system.
-  I'd check to see whether the Eizo is actually in a calibratable mode and not in a hard-wired mode (front panel settings).
- I would then shift the Eizo to the primary head of the display card.
- I would delete any existing previously created profiles from the system.
- I would fire up Color Navigator or the latest version of the Optix software. If these two fail to give decent (not necessarily perfect) results when the screen is acting as a primary monitor, then I would diagnose a system or hardware problem (the puck may be broken). If they worked, then I would start looking for software that gives perfect results, and/or allows me to calibrate both screens - a much harder problem.

If I may politely says so, the best solution for someone with a system above a certain complexity is to call in a color consultant for an hour to fix it.

Edmund

[pobrien3]

It's a pitty that until now, no one with real life experience in hardware calibratable monitors has responded yet. When using a hardware calibratable monitor like the Eizo CE210/240, CGxxx and the NEC's 2190UXi (spectraview) etc... the monitors internal LUT is adjusted while the graphicsboard LUT remains linear (neutral). But I don't know if the Eizo software, after calibrating the monitor automatically resets the graphicscard LUT and updates the profile (WIn2000 > Controlpanel->Display->Color management->Default Monitor profile).

I hope you can find the problem..  ..good luck.
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Thanks René - unfortunately I have to travel on business so can't get back at this for a few days - I'll try to shoot an email to Eizo in the meantime to see if they can offer any advice or at least better documentation..

[pobrien3]

Edmund, thank you for your suggestions - I will try again to calibrate the Eizo after removing the ACD.

I believe my monitor IS in calibratable mode, as after applying the profile the display changes, and the colour settings are dimmed and no longer selectable from the front panel.  The Eizo is already and always has been the primary monitor, and before I started any calibration I already removed (de-installed and deleted) all previous profiles.

The puzzler for me is that the validation SHOWS how poor this profile is, so it seems the puck is working fine (and the ACD re-calibration was OK).

I have to leave this now for several days as I have to travel; in the meantime I'll send some mails off to Eizo and BasICColor.

Peter

[ato]

peter,

try use these setting(not express mode)

gamma L*
6500k
100cd/m2
16bit LUT base profile,CAT02 mode,ICC V4 profile

remember,display type is "LCD"
calibration method must use"software(video LUT)"

and set your monitor  in "custom mode", follow the popup adjust RGB and brightness value.good luck.

[eronald]

peter,

try use these setting(not express mode)

gamma L*
6500k
100cd/m2
16bit LUT base profile,CAT02 mode,ICC V4 profile

remember,display type is "LCD"
calibration method must use"software(video LUT)"

and set your monitor  in "custom mode", follow the popup adjust RGB and brightness value.good luck.
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Yes, be sure to set the front panel buttons/menus to "custom mode". I hae a feeling your monitor may be set into one of the pre-calibrated modes.

Edmund

[howiesmith]

But after you have calibrated your monitor using lets say an Optix XR, how do you actualy verify if the monitor colours are right?

[a href=\"index.php?act=findpost&pid=83691\"][{POST_SNAPBACK}][/a]

It seems to me that any method used to check the calibration would be a good method to calibrate your monitor.  At some point, you just have to trust.

[pobrien3]

Well, I'm back from my travels and got to spend a hour on this darn monitor calibration.  I now have two new profiles which are a lot better than before, and I got them by plugging the puck into a different USB socket!  I made a software calibration as suggested (thanks Ato) and that came out very well indeed - the hardware calibration was not quite as good, but very close and definitely acceptable.  Validation charts attached below: the first is the original result, the second is the hardware calibration in a different USB port, the last is the software calibration in the different USB port.

[attachment=1198:attachment]  [attachment=1199:attachment]  [attachment=1200:attachment]

In searching the net for some clues about this behaviour, someone suggested that you shouldn't use the USB ports in the side of the monitor for its calibration - said he got better results by plugging the puck directly into the computer.  Though I couldn't see what difference that would make I followed the advice and it worked!!

So the thing that's puzzling me now, is why on earth would a software calibration be better than the hardware calibration?  I thought hardware calibration was the holy grail, and that's one of the reasons I bought this monitor.

And the profiles made by Eizo's ColorNavigator were all crap no matter what port I plugged into.

Thanks to those of you who took the trouble to reply, I'm grateful for your advice.

[RedRebel]

The main difference between hardware and software calbration is that when using hardware calibration the total span/range from each single graphicscard's RGB channel is fully used for displaying (selecting) colors.

This means that in the case of hardware calibration the video card can output R:0..255, G:0..255, B:0..255. The RGB adjustments are made inside the monitor in the monitors LUT. THis means the graphics adapter can select 256*256*256=16.8mlj colors.

In case of software calibration the videocards RGB output is manipulated to achieve the same correction. This could mean for example that the effective videocard output is (fictive values): R:6..230, B:23..244, G:10..255. This leads to less selectable colors: 224*221*245=12,1mlj colors.

If you have a display that is almost perfectly calibrated by the factory, the difference will be much less, compared with a bad display that needs a significant amount of compensation.


Windows Vista will support more then 8 bit RGB output. The ATI Fire GL cards are currently the only cards that support 10bit DVI (RGB=1024*1024*1024=1bilj colors), but there is only one monitor that supports it (as far as I now..the NEC 2180 Spectraview Reference). I have this information because I asked NEC if the NEC2690 would support more than 8 bit DVI, it doesn't.


You say the ColorNavigator software is crap, but what software did you use?

[pobrien3]

...You say the ColorNavigator software is crap, but what software did you use?
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Not sure I understand the question - ColorNavigator CE is the calibration software: I used version 1.1.3, having made sure BasICColor was di-installed beforehand.

[RedRebel]

Not sure I understand the question - ColorNavigator CE is the calibration software: I used version 1.1.3, having made sure BasICColor was di-installed beforehand.
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After re-reading you reply I see you did both a software calibration and hardware calibration using different USB ports and software.

On the GretegMacbeth website I found a tool that allows you to examine the curent videocards LUT settings and to reset, save and restore them.

[a href=\"http://www.gretagmacbeth.com/index/products/products_color-mgmt-spec/products_professional-cm/products_pm5-publish/products_pm5-publish_sw.htm]GretegMacbeth Calibration checker[/url] THis way it's easy to check if your videocard is modifing the LUT (it has a profile loaded).

[pobrien3]

René, I downloaded that software and using it I discover that there is a video card LUT setting active even though my monitor is hardware calibrated - looks like there are two calibration settings being applied.  I'm guessing that the videocard setting was in place whilst I did the hardware calibration of my monitor, and it adjusted for the non-linear values coming from the video card.  I'm going to re-calibrate this morning after re-setting the videocard LUT, and see if that gets me a better result.

THANK YOU René!

By the way, seems my experiences with the USB port aren't so crazy - I'm hearing of more instances where using a USB hub creates calibration problems.

[RedRebel]

Ok this brings light in the tunnel. This small software package also allows you to reset the graphicscard LUT, so it's absolutely neutral. Then calibrate your screen again  

[pobrien3]

I'll definitely do that.  As luck would have it, my motherboard died and I've only just got back online again after half a day troubleshooting and eliminating all other possibilities first (my motherboard is 4 years old, none of my components - new videocard included - will work with a new one).  I've got an old temp board in place for now, will get back to calibration once I re-build the PC!