Luminous Landscape Forum

Raw & Post Processing, Printing => Colour Management => Topic started by: jjj on March 06, 2009, 05:36:12 pm

Title: Calibrating Dual monitors
Post by: jjj on March 06, 2009, 05:36:12 pm
I use dual monitors and last year I finally bought a Spyder3 Elite for calibrating [despite my monitors looking fine and outputting with no issues] and I have to say I've never been that impressed with the results since then. The screens also used to look exactly the same before calibrating, but struggled to do so after calibrating
After a recent recalibration, my monitors were unusably awful - I had to output some files using the histogram to judge brightness and check with my laptop. Though after restarting, things were alot better.  
I spoke to the Colour Confidence people at Focus about this and they recommended installing the combo update for 10.5.6 rather than the point update and also the latest Spyder software. I did that.
A couple of days later my NEC 2690s finally arrived and out of the box looked distictly cruddy so out comes the Spyder and the results were not exactly good shall we say. One finally looks passable, possibly a tiny bit blue. The other one looks awful, very warm and murky. The OK monitor doesn't seem to be staying OK either. I tried recalibrating numerous times but they seem to end up at same point.
Seeing as it seems to be similar to issue I had with previous monitors, I'm hoping the new monitors are OK and it's a different and solvable issue.
Any suggestions?
I should also mention I had some weird redraw issue last week, which I hadn't seen since the 10.5.4 update.
Could this be a graphics card/Mac/Cable issue?
 
Someone mentioned to me that with the PC you can get poor results through double profilng, is that even true? But I do not think that is possible with OSX due to how you select profiles.
Title: Calibrating Dual monitors
Post by: Mark D Segal on March 06, 2009, 05:52:59 pm
I've never heard of "double-profiling" a display hooked to a PC. You select a default profile in the Advanced tab in the Color Management tab of your video card Properties for the display concerned and that's it. Everytime you start Windows that profile loads and nothing else is there. What CAN happen, however, is that you, the user, may have two pieces of display profile loading software activated in the Windows Start-Up menu and that indeed will mess things up. You must insure that your Start-up menu only contains ONE set of instructions for loading the default profile and it is the piece of software which loads the default profile you want. I can't comment on Spyder 3, Mac OSX or the NEC 2690 because I don't use any of that equipment - except to say that the NEC 2690 can come bundled with Spectraview which is their custom calibration and profiling package. Presumably if you were to use that and make sure that DDC compliance works and that your calibration settings are OK, you should get decent profiles for that display. There is, however, another thread in the COlorsync Listserve raising a question about whether OSX 10.5.6 is handling DDC compliance properly. I don't know the status of the issue.
Title: Calibrating Dual monitors
Post by: neil snape on March 07, 2009, 02:40:30 am
DDC is broken since 10.5.6 on Mac.
Vista color management is rather crippled from the start. I don't know the details, and still use XP as it is stable and reliable enough.
The cables on a dual monitor set up are important , that they be the same, same length and type if you want to have equal results without influences other than the LUTs loaded in the video card.
IS the Spyder working as expected? Both Colorvision and Gretag colorimeters have been known to fail.
Next step, download a ColorEyes demo good for 10 tries. Make sure you have the Energy settings to no sleep. Carefully go through all the steps, on the primary monitor first, the secondary display after. Same settings. Nothing is infallible but CE is as close as it gets for multiple platform, multiple device software. Oh set the monitor lum in the calibration to 140 CD/m2 and K to about 57-6500 K your choice.

Switch the monitors if the problem persists to see if it's the luts or cables.

Let us know how you make out with this.
Title: Calibrating Dual monitors
Post by: Mark D Segal on March 07, 2009, 07:29:25 am
Neil,

ColorEyes Display is generally an excellent piece of software, and I have been using it for years with a Monaco Optix (X-Rite DPT94) colorimeter on Windows XP Professional. However, the most recent version of CED also has problems with DDC compliance. Integrated-Color is well aware of these issues and says as much on the front page of their website, much to their credit. Nonetheless, if DDC fails to work on one's display, it's a bit of a problem. The fall-back is using the on-display controls to set the necessary display input conditions for the ensuing profiling operation. This can be done, but depending on the display - it is awkward and not fully controllable. I've had this experience with my LaCie 321. Integrated-Color provides excellent support and they told me I've come close enough that my profile is good. Save for one minor issue I still have, they seem to be correct about this. So yes, my experience supports your recommendation, but there are issues, I-C is working on them and users can only hope they succeed; but it only takes one non-compliant link beyond their control in a rather complex chain for the whole DDC business to fail. The general problem afflicting DDC compliance has also been well-documented on the Mac Colorsync List-serve where Tom Lianza (if I remember correctly) pointed to what can only be characterized as a chaotic situation, given the huge number of video cards and displays out there and the absence of anything like an ISO document to help promote the kind of compatbility that would allow DDC to work regardless of the equipment and the O/S. This is a very weak link in the whole colour management chain, and one can only hope that the industry could fix it. But one gets the impression after reading enough about this stuff that there are hardware vendors in this industry who would prefer to frustrate transparency, compatibility and competition.

Turning to your calibration recommendations, I would suggest going easy on the cd/mm2. Working in a dimly illuminated environment as one should, 140 is likely to be too bright, causing the user to adjust the image too dark relative to the desired luminosity reflected by the print. I have found over the years that I've been using an LCD (with about 2 * 60 Watts of shaded room illumination roughly 10 feet away from me) that about 110 cd/mm2 provides a reliable display brightness relative to the prints. There's no hard and fast rule about this. It's trial and error.
Title: Calibrating Dual monitors
Post by: neil snape on March 07, 2009, 07:49:39 am
It's not only IC with problems with DDC. I have in contact with IC about the DDC problems, but also with others. Yesterday in a meeting with Apple and many other dev and hardware developers the situation on DDC is really up in the air. I give full recognition to IC for alerting users on their issues, as not many others have done so. It is also broken in X-Rite and other apps BTW. Who's fault it is exactly is not clear if it is in the VESA specs, DDC specs, new port code, who knows.

In my environment, a lower cd/m2 setting would be preferred but over many years of working with developers on monitor cal and profiling, few video card and monitor combinations tolerate such a low luminance setting especially if the monitor has 10 or less bit luts. In one way you gain matching with the lower lum, but your adverse effects are contouring and variability in the black point , and lut grid point smoothing. I had as others have ( Andrew Rodney, Bruce Fraser  included ) recommended 120 cd/m2 but this is the lowest point for better LCDs , hence other lesser LCDs are best off with a 140 or so luminance.
Title: Calibrating Dual monitors
Post by: Mark D Segal on March 07, 2009, 08:10:15 am
ISO Standard 12646-2008 specifies a RANGE of 80 to 160 cd / m2. Much depends on the ambient light in the studio. I have none of the issues you refer to at 110, using a 10-bit LaCie 321. I'm not disputing your experience with a range of displays and conditions - only saying this is something about which one needs to be pragmatic. Equipment and viewing conditions vary widely.
Title: Calibrating Dual monitors
Post by: jjj on March 09, 2009, 12:53:16 pm
Quote from: MarkDS
What CAN happen, however, is that you, the user, may have two pieces of display profile loading software activated in the Windows Start-Up menu and that indeed will mess things up. You must insure that your Start-up menu only contains ONE set of instructions for loading the default profile and it is the piece of software which loads the default profile you want.
That's probably what was meant by double profiling.

Quote
I can't comment on Spyder 3, Mac OSX or the NEC 2690 because I don't use any of that equipment - except to say that the NEC 2690 can come bundled with Spectraview which is their custom calibration and profiling package. Presumably if you were to use that and make sure that DDC compliance works and that your calibration settings are OK, you should get decent profiles for that display. There is, however, another thread in the COlorsync Listserve raising a question about whether OSX 10.5.6 is handling DDC compliance properly. I don't know the status of the issue.
10.5.6 seems to be seriously problematic.
Title: Calibrating Dual monitors
Post by: jjj on March 09, 2009, 01:07:39 pm
Quote from: neil snape
DDC is broken since 10.5.6 on Mac.
No surprises there!

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The cables on a dual monitor set up are important , that they be the same, same length and type if you want to have equal results without influences other than the LUTs loaded in the video card.
They are the same and I never had any issues until I tried calibrating monitors.

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IS the Spyder working as expected? Both Colorvision and Gretag colorimeters have been known to fail.
Not convinced it is.

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Next step, download a ColorEyes demo good for 10 tries. Make sure you have the Energy settings to no sleep. Carefully go through all the steps, on the primary monitor first, the secondary display after. Same settings. Nothing is infallible but CE is as close as it gets for multiple platform, multiple device software.
Downloading now.

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Switch the monitors if the problem persists to see if it's the luts or cables.
Tried that, doesn't seem to be the issue

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Let us know how you make out with this.
Will do. Thanks to both for your advice.
Title: Calibrating Dual monitors
Post by: jjj on March 09, 2009, 03:45:13 pm
I've DLed ColorEyes Pro Demo and recalibrated.
Left monitor still looks slightly red and darker. It also make a faint buzzing noise, that the other doesn't!?
Right Monitor looks better. For now. It drifted noticably before.