Green color cast in photoshop after monitor calibration 2

[davidl]

Just installed the latest driver... No improvement!

[gcrogers]

You did re-run the monitor calibration routine after installing the new video drivers, right?
-Greg

[davidl]

Yes, I did.

However, it looks like my problem has nothing to do with calibration. When un-calibrated, I still get much better colours (and smoother gradients) in Photoshop when proofing in Monitor RGB than when not proofing.

Calibration makes the colours look more natural (less blueish), but I still have to proof in Monitor RGB to get accurate results.

Therefore, I can only work in the sRGB space.

[DavidW]

Yes, I did.

However, it looks like my problem has nothing to do with calibration. When un-calibrated, I still get much better colours (and smoother gradients) in Photoshop when proofing in Monitor RGB than when not proofing.

Calibration makes the colours look more natural (less blueish), but I still have to proof in Monitor RGB to get accurate results.

Therefore, I can only work in the sRGB space.

I realise you've already been through so much - but proofing in the Monitor RGB space is simply turning off screen colour management in Photoshop. You're using the LUT data but nothing else from your profile working this way - and that's not accurate, even for sRGB. Monitor RGB gets you no closer to proper colour management - all you're doing is making Photoshop emulate applications that aren't colour managed. That setting is there for previewing web graphics on your particular monitor, and not much else.


Bearing in mind that you're complaining of a blue tint, your choice of white point may be to blame. 6500K (well, if your calibration solution supports it, D65) is typical, but maybe your monitor, when uncalibrated, is rather warmer than that. This feels unlikely - usually uncalibrated LCD monitors are to the cool side (9300K is not unknown). Nevertheless, it may be worth experimenting with different white points, including profiling to the monitor's 'native' white point if you have that option - much as I'm struggling to see why this would be the issue.

Whilst we're still on the subject of white point, some LCD monitors have an on screen display option to choose the white point. Whilst that sounds like the correct thing to do before calibrating (and is usually the correct thing to do on a CRT, where you're changing the relative gain of the three input amplifiers or similar), it's usually a mistake on an LCD. Leave an LCD monitor set at the native white point, and leave it to the calibration setup to get the white point right. (I've verified this with my setup in Monaco OPTIX XR Pro - the deltaE is worse if I set the white point using the OSD and calibrate than if I leave my panel at its native white point).

A final thing that may be in play is the contrast setting on your LCD if it has one. I drive my monitor using DVI, so the only setting available is brightness which changes the backlight intensity (DVI also gives a sharper picture than using VGA). If you do have a contrast setting on the monitor, try adjusting it before reprofiling - ideally recording the values you've tried.


You haven't said is what monitor you're using - it could be that the monitor itself is bad. A 6 bit TN panel is never going to calibrate well - in fact, no TN panel is that good for serious colour work because of the contrast and colour shifts as you move your head around (which is why laptops are poor for colour critical work). If you have one of those 6 bit abominations that produces 16.2 million colours by frame rate control (check the specification - if it's 16.2 million colours rather than 16.7 million colours, this is probably what you have), that would certainly explain your duff gradients.


I'd argue that gradients are a very poor way to evaluate a profile anyway. A primary colour gradient, say a gradient from R 0 G 0 B 255 to white (R 255 G 255 B 255) will always look smoother in monitor RGB because you're simply varying the R and G values from 0 to 255 along the gradient. With colour management, the blue end of my hypothetical blue gradient is no longer R 0 G 0 B 255 - it's whatever R 0 G 0 B 255 in the working colour space is when transformed to the monitor colour space. The same is true of every intermediate value along the gradient - including white.

R 25 G 13 B 234 doesn't represent a unique colour until you define a colour space. If you say "Monitor RGB", then you get whatever that represents on your monitor with the LUT taken into account. If you say "sRGB" then it represents a particular colour - the colour management system will do some sums to transform R 25 G 13 B 234 in sRGB to the nearest R G B values on your monitor to display the right colour. It could be R 20 G 15 B 225.


Indeed, having the colour management system engaged could explain the colour cast you're observing on white. If you're comparing to white with the LUT loaded but colour management off, that will be R 255 G 255 B 255 transformed by the LUT in the non-colour managed setup. R 255 G 255 B 255 in the colour managed setup goes through a transformation from the white point of the colour space you're using before going through the LUT, and it's possible that the white point of the colour space you're using is out of gamut, hence the apparent colour cast you're seeing. If that's the case, the cast will only affect pure white or very nearly pure white. The in gamut colour chosen by the colour management system for white in the colour space you're working in might not necessarily be neutral.

The banding your image shows is worse than I see on my monitor (Dell 2007WFP with an S-IPS panel, calibrated to D65, 2.2 Gamma with Monaco OPTIX XR Pro in 99 patch table mode), but such banding isn't unknown.


Updating to Photoshop CS2 9.0.2 is a good idea anyway, as there's various bug fixes in 9.0.2 - but I don't think it's going to change anything here.

If you have any non-Adobe colour managed software (such as Canon's Digital Photo Professional if you have a Canon DSLR - though be aware that you have to select the screen profile in DPP as it doesn't pick it up automatically) does that work OK, or is that doing the same as Photoshop?



I strongly suggest you get away from the gradients, and other things that are potentially misleading and are unrepresentative of the colours in your photographs anyway. I suspect your settings are right, though your monitor may be a poor one, making things worse. The Gretag Macbeth calibration setup you're using is a good product - if it was fatally flawed, the Internet would be full of reports about it.

The other thing is, as I already hinted at, you have to give your eyes chance to adjust to working on a calibrated monitor. You get used to the flaws of your monitor when uncalibrated or partially calibrated.


Instead of looking at gradients, look at images like a Gretag Macbeth ColorChecker chart (if you have a ColorChecker and illumination that is 6500K or thereabouts, that will be an even better starting place). Look at photos too - if you have a profiled printer and 'daylight' illumination, how do the colours compare? You could also compare a grey card and mid grey on screen - though be aware that this, too, may look slightly different if your room illumination isn't 6500K or thereabouts. Nevertheless, if you're looking for colour casts on neutral shades, it's best done with mid grey. (Black can be especially misleading on a monitor - IPS monitors can impart something of a violet hue to dark blacks because of the way the screen works - no screen technology is perfect, but of the three main types of LCD screens, my favourite is IPS for photographic work, and I do own examples of all three major types - a TN laptop, a *VA 17 inch LCD and an IPS 20 inch LCD).

In conclusion - what, if any flaws are you seeing in realistic use with colour management enabled, rather than with contrived test cases. Are you seeing banding in skies, for example?



David

[Kevgermany]

just struck me - proofing should be using an output profile - such as the printer profile. The screen profile is also an output profile, so it looks as if this is correct and explains the correct colours there.

So the problem looks as if it's a mismatch between the screen profile that windows loads and the screen profile that you're using in PS for normal editing. Sorry to be so vague.

What colour space are the blue gradients in?

I've had problems with prints showing a blue shift - the whites turned a slightly deeper shade of blue that the 'white' of duck's eggs. I eventually traced it down to expeimenting with absolute colorimetric intent at print time to see what happened - and then forgetting about it

[DavidW]

Proofing in Monitor RGB is something of a misnomer. What it actually means is "do not use the monitor profile to display this image" or, putting it another way "show this image on screen as you would see it in a non-colour managed application".

Proofing in Windows RGB does much the same thing, except that it adjusts to 2.2 gamma. This is a no-op on Windows which uses 2.2 gamma anyway; it's the same as selecting Monitor RGB.

Proofing in Macintosh RGB is the same as Windows RGB, except that it adjusts to the (obsolescent) 1.8 gamma setting used in some circumstances by older Macs.

As I said earlier, all three of these settings really exist to deal with work targeted at non-colour managed web browsers, though, of course, the results will differ from monitor to monitor. Only the LUT is used, not any other elements of the screen profile.


Other than that, proofing doesn't appear to come into this - davidl's screen shot shows RGB/8*) on the title of the 'managed' gradients, which means, RGB mode, 8 bits per pixel and the * means the image is not in the RGB working space selected in Photoshop. I see it a lot, as I tend to work on images in ProPhoto RGB, whilst my CS2 working space is sRGB (synchronised across the entire Creative Suite).

I'm sure we've covered this already, but the RGB working space should be a device-independent colour space such as sRGB, not your monitor profile. Meanwhile, whilst you're trying to sort this out, Proof Colors should be off (see the View menu in Photoshop).



David

[grantp]

Hmm.

Further to my observations on another thread ...

The gradient shots that davidl posted a while back are exactly what I see on my notebook screen for the blues - except that I get more banding and a sharper cut over from blue to the pinker shade. (Lightroom in my case but also LightZone beta 2.2 the same.)

I've run the profiling (i1 d2) a few times now with little or no differences even forcing certain settings just to see what happens. (Luminance and colour temp for example.)

Whilst there can be differences the most notable thing is the the i1 summary shows the red and yellow graph lines pretty much spot on the slope but the blue drops well below from quite low down the scale but then runs more or less parallel.

I think what it is telling me is that the screen/driver can't hack it for blue when 'properly' calibrated. This might not be so bad for general use - the Adobe Gamma test program gave an acceptable result for my purposes anyway other the some printer output anomalies sometimes. But clearly if I need proper colour matching - my 'pink' thread being a case in point - I either need to work out the adjustment values (which could be challenging as it will not be an entirely fixed value across the range) or buy a more useful monitor for office use.

I do have an old Dell CRT monitor from about 10 years ago which I will check out (if it will work run from the notebook) when I have time.

My Sony TFT screen seems a little more consistent although having profiled that too the deepest blue cotton reel (extreme right) now tends to purple when I view the downloaded test chart jpg. In a browser window it still looks mainly deep royal blue except for the multi-printer comparisons (Epson 1400 for example) where the Epson R1800 scan also has a slightly purple tendency, though not as pronounced.

So, whilst I have a few ideas to play with I doubt they will be good ones.

In which case - who can recommend a good cost effective, preferably flat screen monitor? I saw some very nice looking Eizo and Lacie products at Focus but I'm not sure my requirements are critical enough to justify the costs at the moment ...

[davidl]

David,

Wow, thanks a lot for the lengthy explanation!

You haven't said is what monitor you're using - it could be that the monitor itself is bad.

Yes, I think it is bad. I must have overrated what could be achieved with a laptop monitor... I naively thought it could be good enough once calibrated... (It's a Dell Inspiron 6400 UltraSharp "with TrueLife", with the Intel 945GM chipset).

I'd argue that gradients are a very poor way to evaluate a profile anyway.

I agree. I tested those gradients when trying to understand what was happening, after observing serious posterization, banding and oversaturation in many photos (in Photoshop, in any colour space). I think those gradients only help confirm that there is a problem with my setup. I shouldn't be judging colours on a system that provides such poor gradations...

Too many colours out of gamut on this monitor, maybe?

Instead of looking at gradients, look at images like a Gretag Macbeth ColorChecker chart (if you have a ColorChecker and illumination that is 6500K or thereabouts, that will be an even better starting place).

Could be interesting. However, I think the charts will look mostly fine when not colour managed, and look bad when colour managed in Photoshop! :-/

David.

[DavidW]

There's a common thread between both David and Grant's problems - Eye One Display 2. It may be that it's not working optimally on poor screens.

You haven't said is what monitor you're using - it could be that the monitor itself is bad.

Yes, I think it is bad. I must have overrated what could be achieved with a laptop monitor... I naively thought it could be good enough once calibrated... (It's a Dell Inspiron 6400 UltraSharp "with TrueLife", with the Intel 945GM chipset).

Laptop screens are universally quite poor for colour critical work. Most are TN based screens - if you see a contrast and colour shift as you move your head around the screen, that's what you're dealing with. I have a Dell Latitude D600 - not the most recent laptop, but it's not too shabby. I use it when mobile - but try to avoid as much Photoshop work on it as I can because of the limitations of the panel, even when calibrated. I find I just can't judge colour accurately on a TN panel, quite apart from it not calibrating that well.

I'd argue that gradients are a very poor way to evaluate a profile anyway.

I agree. I tested those gradients when trying to understand what was happening, after observing serious posterization, banding and oversaturation in many photos (in Photoshop, in any colour space). I think those gradients only help confirm that there is a problem with my setup. I shouldn't be judging colours on a system that provides such poor gradations...

Too many colours out of gamut on this monitor, maybe?

Out of gamut colours are part of the problem, I'd think - though not the whole problem. Monaco OPTIX XR Pro allows me to assess the performance of a screen after profiling. On my Latitude D600, three of the Gretag Macbeth ColorChecker colours are out of gamut (or is it four). Anyway, the overall deltaE for the ColorChecker colours is nearly 8, which is horrendous.

I do wonder if the poor gradients are an artefact of Eye One Display 2 when used on a poor screen - but the primary problem here is the screen.

Instead of looking at gradients, look at images like a Gretag Macbeth ColorChecker chart (if you have a ColorChecker and illumination that is 6500K or thereabouts, that will be an even better starting place).

Could be interesting. However, I think the charts will look mostly fine when not colour managed, and look bad when colour managed in Photoshop! :-/

That could be.


If you have to use the laptop for photo work at a fixed location, consider hooking up a decent external monitor, and calibrating that. You can always use the panel for toolbars and similar.

Grant was asking for monitor recommendations. I have a Dell 2007WFP on my main machine, which I like - it's a decent 16:10 widescreen monitor. Some criticise it for only being 1050 pixels high (they'd rather it was 1080 for HDTV use), but that's not an issue for me. Apparently some of the most recent 2007WFPs use a different panel to the LG Philips S-IPS panel in mine. The alternative panel is either MVA or PVA, and which I regard as somewhat inferior to S-IPS for photographic use, but, it's no disaster. Especially if you can get an IPS based one, it's a good buy. Avoid Revision A00 units; they have broken firmware that always has Faroudja processing on which causes various unwanted screen artefacts.

deltaE on the ColorChecker colours post calibration on my setup is about 1.7. Anything under 2 is acceptable in just about any environment.



David

[grantp]

There's a common thread between both David and Grant's problems - Eye One Display 2. It may be that it's not working optimally on poor screens.

The other common thrad being a Dell noteboook. 8600 with the top resolution screen (USXGA? or is it WSXGA, I can never remember) running at 1920x1200. nVidia GeForce FX Go5200 graphics card.

It's a great screen for resolution and the colours come out really well - except for the blues in my case.

I'm wondering if there is some additional effect in play here, post calibration. I have some ideas to play with but time is short in the next week or so.

Grant

[davidl]

I do wonder if the poor gradients are an artefact of Eye One Display 2 when used on a poor screen - but the primary problem here is the screen.

As you say, the primary problem is probably the screen. When un-calibrated, it's showing the same bad gradients (with colour management in Photoshop), and smooth gradients when not colour managed.

The Eye-One did correct the monitor's colour casts very nicely, but did not fix the gradients. And since those bad gradients show up only in colour managed apps, I guess there's not much the Eye-One can do.

Same problem in Lightroom. I did not try other colour managed apps beside Adobe's, but I think Adobe must have implemented colour management right.

Thanks for the help!

David.

[grantp]

... , but I think Adobe must have implemented colour management right.

Yes, you would certainly hope so.

Then again some of their applications do seem to have some odd quirks when installing, operating and managing memory, amongst other things.


Grant

[grantp]

Just spent a happy hour or so running a number of calibrations on the Dell notebook specifying different White Point values (and attempting to get the Luminance somewhere close to the target.

You can find the screen dumps of the process summary results in a MS Word document here

The results are for the runs I bothered to keep and are in the order I ran them.

To me it is interesting that the more typical white balance temps have the greatest divergence on blue whilst the other colours are pretty consistent but the best 'balance' across all colours (though not especially accurate by the looks of the graph) appear to be with the colour temp set between 9000 and 10,000K.

It's not too easy to spot at the size of the screen but the colour gamut triangle varies marginally as well.

Interesting I thought. I'll compare prints in daylight, probably in the morning. The on screen preview looks OK - but that does not always mean much as we know!


Grant

[davidl]

Although the conclusions were already clear enough, I did some more tests...

I took an old CRT monitor out of the closet, plugged it in, defined it as the primary monitor (this is required for Photoshop to colour manage it), calibrated it with the Eye-One. In the end, colours were looking nice in Photoshop on the CRT, with no posterization and no banding.

So at least this tells me that both my Eye-One and my graphics card are working ok. The problem is the LCD. Apparently it is worse than an 8 years old CRT that needs 5 minutes of warm up before showing anything!

The lesson is: Calibration hardware can't make up for bad monitors! (Not that this obvious fact needed any demonstration...)

David.

[DavidW]

So at least this tells me that both my Eye-One and my graphics card are working ok. The problem is the LCD. Apparently it is worse than an 8 years old CRT that needs 5 minutes of warm up before showing anything!

The lesson is: Calibration hardware can't make up for bad monitors! (Not that this obvious fact needed any demonstration...)

It's always worth having the data point though. Laptop screens are optimised for many things. Colour rendition is not one of them - I find laptops dreadful for colour critical work.

Are there any laptops that have anything other than a TN based panel?



David