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Author Topic: Changing my monitor calibration system  (Read 6354 times)
ErikKaffehr
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« Reply #20 on: January 14, 2010, 11:24:39 PM »
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Hi,

Yes, the Color should adjust the LUT so that you get the right brightness. I'm using a Color Munki, and with that tool there is a step in the calibration process where you can adjust brightness.

As a sanity check you may check out some web page for visual profiling of screens like this one:

http://www.normankoren.com/makingfineprint...html#gammachart

On thing you could try is to take a some standard image (like the image on Andrew Rodney's web page: http://www.digitaldog.net/files/Printer_Test_file.jpg.zip ), process to your taste and post it
on this forum. This should indicate if you have a serious issue.

Regarding "gamma" I'd use 2.2 regardless of you having a Mac, another alternative is to use "Native gamma".

Sorry I cannot help!

Best regards
Erik

Quote from: JessicaLuchesi
Hey Erik,

No, I didn't. How can I measure it using either the Spyder3 Pro software, or the ColorEyes package? I did however set, and try to vary, the target luminance while calibrating. I can manually set it from the system preferences, yes. I tried dimming, but I didn't feel I was getting any closer to solving the problem. I think, since the ColorEyes software adjusts everything on the LUT ( from what I inferred ), I should try to set it there. Not sure if I am correct. Maybe I am indeed running after my own tail, and getting just slightly closer, but without any definite solutions

Thank you for the tip on the printing evaluation, but I really don't print. My files go directly to editors, and even they don't have perfect proofing of the prints. They rely on experience to sort out problems. I think my best chance, is to maybe match a patch image to the GretagMacbeth 24-patch target, which is a known, tested reference. Still, I guess it's only as good and accurate as my eyes. And even then, not really an official image, but one provided as support material to the Real World Color Management book.
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ErikKaffehr
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« Reply #21 on: January 15, 2010, 12:14:50 AM »
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Hi,

One thing that you should keep in mind that the black box on the Macbeth card is not black, it's more like dark grey. You could check out this page for black levels:
http://www.normankoren.com/makingfineprint...html#gammachart

I don't know about black luminance, because I don't have it my tool set. Regarding white luminance it's really depends on your viewing environment. The 100 cd/m2 seems like a reasonable value to me.

Best regards
Erik


Quote from: JessicaLuchesi
Quick note, opening the ProPhoto and LAB versions of the 24-patch target from the book's support site had some minute differences when comparing my own screen to the physical X-rite target. The LAB file was almost spot on. The only issue still to be looked upon, is the brightness, not really color matching. The bottom gray patches still seem to be really bright, compared to the card. It's also noticeable on the color patches, but it's impossible to ignore on the gray ones.

Anyone has any idea how to solve this? Maybe changing the target white or black luminance while calibrating?

The ColorEyes Display Pro suggests 120cd/m2, but I'm setting to 100cd/m2 and it still seems too bright. Is there some sort of "standard" value to be used?
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Tim Lookingbill
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« Reply #22 on: January 15, 2010, 03:15:52 PM »
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A while back I created a color target for assessing display calibration accuracy especially for gamma and color matrix formula transform in color managed apps.

These colors were derived from years of noticing their hue/saturation response shift in Photoshop on a Mac system when loading different display profiles that used inaccurate color matrices encoded within their build.

Some of these matrices=(mathematical descriptors of combined display colorant purity's and color temp) are embedded within the default profile built by the system whenever a new display is connected and not profiled. Most displays somewhere in the late '90's had their color responses measured and written into their ROM chip by the factory in standard EDID format. Often they either were inaccurate or were written in such a way that induced the OS to create a corrupt default profile causing hue/saturation shifts in Photoshop.

Mac's eyeball calibrator in OS X automatically derives these EDID numbers whenever you see "Color LCD" or the manufacturer's brand name in a profile the user didn't install.

Anyway, here's what to visually test for in this target, it's in the AdobeRGB space so it needs to be viewed in a color managed app:

The small squares in the center of the bigger squares should not be more noticeable in luminance than the differences seen between the solid black square and the gray square right above it except of course for the Golden Yellow square and blue gradient-(my homage to Maxfield Parrish).

The red in the Xrite color chart should not look orange or magenta. The baby on the far right should have a more noticeable amount of yellow in its peachy pink tan complexion compared to the pink baby second from the left. And none of the colors in the entire chart should be glowing (blooming) or appear over saturated.

Hope it helps, cheers!

Tim Lookingbill

[attachment=19478:ColorSqu...inTarget.jpg]
« Last Edit: January 15, 2010, 03:16:59 PM by tlooknbill » Logged
JessicaLuchesi
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« Reply #23 on: January 15, 2010, 05:34:59 PM »
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Quote from: tlooknbill
A while back I created a color target for assessing display calibration accuracy especially for gamma and color matrix formula transform in color managed apps.

These colors were derived from years of noticing their hue/saturation response shift in Photoshop on a Mac system when loading different display profiles that used inaccurate color matrices encoded within their build.

Some of these matrices=(mathematical descriptors of combined display colorant purity's and color temp) are embedded within the default profile built by the system whenever a new display is connected and not profiled. Most displays somewhere in the late '90's had their color responses measured and written into their ROM chip by the factory in standard EDID format. Often they either were inaccurate or were written in such a way that induced the OS to create a corrupt default profile causing hue/saturation shifts in Photoshop.

Mac's eyeball calibrator in OS X automatically derives these EDID numbers whenever you see "Color LCD" or the manufacturer's brand name in a profile the user didn't install.

Anyway, here's what to visually test for in this target, it's in the AdobeRGB space so it needs to be viewed in a color managed app:

The small squares in the center of the bigger squares should not be more noticeable in luminance than the differences seen between the solid black square and the gray square right above it except of course for the Golden Yellow square and blue gradient-(my homage to Maxfield Parrish).

The red in the Xrite color chart should not look orange or magenta. The baby on the far right should have a more noticeable amount of yellow in its peachy pink tan complexion compared to the pink baby second from the left. And none of the colors in the entire chart should be glowing (blooming) or appear over saturated.

Hope it helps, cheers!

Tim Lookingbill

[attachment=19478:ColorSqu...inTarget.jpg]

Thanks Tim,

I also did something similar myself. Since I do own a ColorChecker Passport, I went the dumb way. If the purpose of that target and software is to generate a proper camera profile, then, by properly lighting it and metering it, that image, once white balanced and profiled, should give an image of the target comparable to the target itself.

The several online target-images available looked "washed out" for me, and I was thinking either my screen or my Spyder had a problem. But both your photo and my own image of the target ( with the DNG profile created by the CC Passport plugin ) were spot on. My own image a bit more than yours, but both were more accurate to the actual physical target ( placed side by side with the screen ) than the downloaded patches. But even the downloaded patches didn't have color changes, as I could see the same colors, without even slight variations, it just looked "washed out".

I also did the test suggested on "Real World Color Management", page 220 ( Chapter 9 - Figure 9-1 ), which is their Black Point Check. They state an excellent calibration system should see a difference between level 0 and 1, and a typical system, around 5 or 7. I noticed a change right on the first level, without color casting.

I guess that leaves me with some peace of mind. Yes, it's a notebook screen, it will never be perfect, but at least my Spyder doesn't seem to be giving me false colors, or making images so bright, I could get an exposure wrong, which were my biggest fears. I still want to go towards a i1Pro and good external monitor when my budget allows. But I don't think I need to replace my colorimeter right now. Maybe I got lucky and got one of the "good" Spyder3 units.

Anyway, it was also a couple of days of testing every possible white luminance, black luminance and recalibrating and comparing the CC Passport to images of the target, trying to find significant shifts, aberrations, and in the end all the hard work turned out fine

Thanks everyone, I really mean it, all the help in this forum was really important, even to wonder what else I could check and do and test and see how to improve.

And here's what I did to manage a decent calibration on my MacBook Pro 13" screen.

Software: ColorEyes Display Pro
Hardware: Spyder3
Monitor Settings: Apple Cinema Display,iMac, Laptop
Profile Settings: ICC v4
White Point Target: D65, 110cd/m2
Gamma: 2.2
Black Point Target: 0.35cd/m2

I guess it helps. By the way, the native white luminance of my display is around 195cd/m2. And I did add a few custom gray balance points ( 138, 114, 86, 74, 54, 36 ), because I could see some banding forming on the scale.
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Desmond
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« Reply #24 on: January 15, 2010, 10:02:07 PM »
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Put aside the unit to unit inconsistency of spyder 3 pro, the PRO software is simply not good enough because of the manual setting of the target, calibration. ELITE softWare is a must for user who expect good softproofing result. The boiled down most important brench mark of one's system in respect of color management.      
In short if you are spared of the color shift issue of you spyder3 hardware, please upgrade to elite. The upgrade price is just the price difference between Pro and Elite , so you won't regret not to buy Elite in the place.
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Regards,

Desmond
Desmond
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« Reply #25 on: January 15, 2010, 10:04:44 PM »
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Oops
I mean ....because of the manual setting of the target is missing...
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Regards,

Desmond
JessicaLuchesi
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« Reply #26 on: January 16, 2010, 05:49:08 AM »
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Quote from: Desmond
Oops
I mean ....because of the manual setting of the target is missing...

Yes, but I solved that by using the ColorEyes Display Pro software, instead of the Spyder Pro software.  Worked like a charm
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Scott Martin
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« Reply #27 on: January 16, 2010, 06:07:26 AM »
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Quote from: JessicaLuchesi
Yes, but I solved that by using the ColorEyes Display Pro software, instead of the Spyder Pro software.  Worked like a charm
Glad to hear it. CEDP has been a strong solution for demanding professionals for quite some time now. From my observation, people often start with a Huey or EyeOneDisplay but eventually make their way up to CEDP. Their iterative calibration process and white point tuning features are key.
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