Color management with the BenQ SW270C, Windows10, LRc

JoachimStrobel said:

Hi,

what you say seems OK. However, that still leaves the problem, that I cannot change the brightness of the custom cal. slot.

Click to expand...

I can calibrate the user calibration slots to whatever brightness I want. Have I misunderstod your point?

JoachimStrobel said:

Nor can I change to SRGB to check my photos. LRc Softproofing does not do it.

Click to expand...

Can you explain why LR (classic) Softproofing doesn't work for you?

JoachimStrobel said:

What would have been needed is a Hardware LUT that works on the monitor´s predefined Colors Slots. Like a Master setting. I am afraid Benq took a marketing short cut.

Click to expand...

Can you explain that a bit more please? The hardware LUTs in the three programmable slots - Callibration 1, Calibration 2 and Calibration 3 - can each be programmed for colour space, white point, black point and TRC.

JoachimStrobel said:

However, another great feature of this monitor helps: The side by side scree option PBP.

My main connection is Display Port, the secondary one is DVI. I can now set the left side to AdobeRGB (Monitor default with ICC) and the right side to SRGB (with the ICC) and move the LRc window from left to right and it works nicely. (see below, of coures no differences should be visible as this is an SRGB Iphone photo, but I am surprised a small difference can still be seen.).

Doing comparisons I conclude that the new PME native display cal checks out as being 100% AdobeRGB but compares badly to the default AdobeRGB mode. The PME calibrated SRGB mode compares horribly to the default RGB mode.

Click to expand...

Personally I see no need to use the factory sRGB and Adobe RGB modes (or any other built-in modes). What am I missing?

JoachimStrobel said:

So I stay with the factory settings for the moment. I return my SpyderX for a new one and check if it had a bad day.

Click to expand...

--
Simon

Simon Garrett said:

JoachimStrobel said:

Hi,

what you say seems OK. However, that still leaves the problem, that I cannot change the brightness of the custom cal. slot.

Click to expand...

I can calibrate the user calibration slots to whatever brightness I want. Have I misunderstod your point?

Click to expand...

Sure, but you can not change the brightness afterwards. For prints I might want 80cd, for screens 120cd. Sure, I can generate two calibrations for that, then I have filled 2 slots. and can not do 140 or 160cd quickly

Simon Garrett said:

Simon Garrett said:

Nor can I change to SRGB to check my photos. LRc Softproofing does not do it.

Click to expand...

Can you explain why LR (classic) Softproofing doesn't work for you?

Click to expand...

It works as it shows a shading where colors are off-gamut. But it does not transpose the photo from AdobeRGB into sRGB

Simon Garrett said:

Simon Garrett said:

What would have been needed is a Hardware LUT that works on the monitor´s predefined Colors Slots. Like a Master setting. I am afraid Benq took a marketing short cut.

Click to expand...

Can you explain that a bit more please? The hardware LUTs in the three programmable slots - Callibration 1, Calibration 2 and Calibration 3 - can each be programmed for colour space, white point, black point and TRC.

Click to expand...

Yes, they can. But it would be smarter to have a differential hardware calibration that would then work on all the factory modes which take up so much of the monitor´s GUI but become useless after the calibration runs out.

Simon Garrett said:

Simon Garrett said:

However, another great feature of this monitor helps: The side by side scree option PBP.

My main connection is Display Port, the secondary one is DVI. I can now set the left side to AdobeRGB (Monitor default with ICC) and the right side to SRGB (with the ICC) and move the LRc window from left to right and it works nicely. (see below, of coures no differences should be visible as this is an SRGB Iphone photo, but I am surprised a small difference can still be seen.).

Doing comparisons I conclude that the new PME native display cal checks out as being 100% AdobeRGB but compares badly to the default AdobeRGB mode. The PME calibrated SRGB mode compares horribly to the default RGB mode.

Click to expand...

Personally I see no need to use the factory sRGB and Adobe RGB modes (or any other built-in modes). What am I missing?

Click to expand...

Sure, but 80% of the monitor´s GUI is occupied with that. And they can have their brightness and contrast changed....

Simon Garrett said:

Simon Garrett said:

So I stay with the factory settings for the moment. I return my SpyderX for a new one and check if it had a bad day.

Click to expand...

Click to expand...

I spend some time with my Sws270C and like to add a couple of remarks to my previous posts:

The example where I show the side_by_side mode is not strictly valid, as LR changes color space only once the window is completely moved from one screen to the other. Until then it drags the original space into the other monitor.

The newer Nvidea drivers have a switch in their colour management labelled “reference”. That blocks access to the card´s LUT by ICC profile extensions. Even though PME generated profiles do not modify the card´s LUT entry, they need access. The PME calibration software will fail if the said switch is set.

When connected to my GTX970, the Sw270 (and my other monitors) show a slightly too cold color temperature of 7100K for the Sw270´s default modes when measured with a SpiderX. I am not sure if that is a sign of a broken GTX970 or if indeed graphic cards have their own color signature (like amplifers?). For the SW270 I fixed that by assigning the sRGB to CUSTOM1 profile and manually tweaking the color temperatur to 5900k.

I have seen the situation, where the main "Screen adjust window" identified two monitors differently than the “identify” button in color management. That can cause problems. It can be also seen in the Nvidea driver, where the monitor number is assigned strictly by the hardware ports while the "Windows screen" thingy seems to follow a different logic.

The PUK can be useful. As most Windows programmes are not color matched, one can easily assign the AdobeRGB icc profile to the monitor and have the PUK select SRGB and work correctly within Windows. Whenever Lightroom starts it will read the AdobeRGB setting and I can quickly use the PUK to switch the monitor to AdobeRGB space.

Finally, I spent hours being caught by the Windows “nightshift bug”. Even though Nightshift is set to off, it is applied, lowering the color temperature from 6500 to 3300k (that depends on the monitor). The web has some hints how to fix it:
Log-off and on
Simply toggle the switch
Delete two entries in the Registry
Turn off Virtual Visualisation in the Bios.

For me it was the registry.

JoachimStrobel said:

Simon Garrett said:

JoachimStrobel said:

Hi,

what you say seems OK. However, that still leaves the problem, that I cannot change the brightness of the custom cal. slot.

Click to expand...

I can calibrate the user calibration slots to whatever brightness I want. Have I misunderstod your point?

Click to expand...

Sure, but you can not change the brightness afterwards. For prints I might want 80cd, for screens 120cd. Sure, I can generate two calibrations for that, then I have filled 2 slots. and can not do 140 or 160cd quickly

Click to expand...

Point taken. I had perhaps missed that as I want only one brightness, at around 100-110cd/m2.

I've not found the need for anything brighter, but perhaps that's because the ambient light in my study is fairly low. Do you work with brighter ambient light and so need brighter monitor calibration?

JoachimStrobel said:

JoachimStrobel said:

JoachimStrobel said:

Nor can I change to SRGB to check my photos. LRc Softproofing does not do it.

Click to expand...

Can you explain why LR (classic) Softproofing doesn't work for you?

Click to expand...

It works as it shows a shading where colors are off-gamut. But it does not transpose the photo from AdobeRGB into sRGB

Click to expand...

I don't understand that, and perhaps we're at cross purposes.

In LR soft proofing, it highlights in red the areas of clipped out-of-gamut colours if you click the icon above and to the right of the histogram, but if you turn that off (click it again) then it shows all colours as they would be in the emulated colour space. Effectively, it does transpose the photo from LR's working space (which is ProPhoto RGB, not Adobe RGB) into the emulated space, such as sRGB.

Or are we talking about different things?

JoachimStrobel said:

JoachimStrobel said:

JoachimStrobel said:

What would have been needed is a Hardware LUT that works on the monitor´s predefined Colors Slots. Like a Master setting. I am afraid Benq took a marketing short cut.

Click to expand...

Can you explain that a bit more please? The hardware LUTs in the three programmable slots - Callibration 1, Calibration 2 and Calibration 3 - can each be programmed for colour space, white point, black point and TRC.

Click to expand...

Yes, they can. But it would be smarter to have a differential hardware calibration that would then work on all the factory modes which take up so much of the monitor´s GUI but become useless after the calibration runs out.

Click to expand...

Yes, that makes sense.

JoachimStrobel said:

JoachimStrobel said:

JoachimStrobel said:

However, another great feature of this monitor helps: The side by side scree option PBP.

My main connection is Display Port, the secondary one is DVI. I can now set the left side to AdobeRGB (Monitor default with ICC) and the right side to SRGB (with the ICC) and move the LRc window from left to right and it works nicely. (see below, of coures no differences should be visible as this is an SRGB Iphone photo, but I am surprised a small difference can still be seen.).

Doing comparisons I conclude that the new PME native display cal checks out as being 100% AdobeRGB but compares badly to the default AdobeRGB mode. The PME calibrated SRGB mode compares horribly to the default RGB mode.

Click to expand...

Personally I see no need to use the factory sRGB and Adobe RGB modes (or any other built-in modes). What am I missing?

Click to expand...

Sure, but 80% of the monitor´s GUI is occupied with that. And they can have their brightness and contrast changed....

JoachimStrobel said:

JoachimStrobel said:

So I stay with the factory settings for the moment. I return my SpyderX for a new one and check if it had a bad day.

Click to expand...

Click to expand...

Click to expand...

--
Simon

Simon,

I would not use 140 or 160cd as my room is quite dark, but I just might want to do that for checking. I agree that this is not a must, but then, changing brightness is a nice thing to have.

I checked again. I am in LRc develop-softproof. I am in AdobeRGB and can change the Profile to sRgb The shading changes, even when selecting AdobeRGB as the photo is in ProPhoto. But no, the image does not change a bit. I can see what SRGB is missing, the blue shades to the left and right. And I can, as per my last posts, visualize that with side_by_side screens. But within LR nothing changes. I read another post somewhere that conformed that,

JoachimStrobel said:

Simon,

I would not use 140 or 160cd as my room is quite dark, but I just might want to do that for checking. I agree that this is not a must, but then, changing brightness is a nice thing to have.

Click to expand...

Understood.

JoachimStrobel said:

I checked again. I am in LRc develop-softproof. I am in AdobeRGB and can change the Profile to sRgb

Click to expand...

Do you mean: in Lightroom, and you soft proof to Adobe RGB and then change to soft proof in sRGB?

JoachimStrobel said:

The shading changes, even when selecting AdobeRGB as the photo is in ProPhoto. But no, the image does not change a bit. I can see what SRGB is missing, the blue shades to the left and right. And I can, as per my last posts, visualize that with side_by_side screens.

Click to expand...

How do you mean with side-by-side screens? I didn't understand this bit. What software are you using to see them?

JoachimStrobel said:

But within LR nothing changes. I read another post somewhere that conformed that,

Click to expand...

I don't understand. Nothing should change in LR except when soft proofing, when it certainly does change. I've just tried a similar sunset to the one you show, and there's a clear difference (in the image I'm using, in some bright orange colours) between soft proofing in sRGB and soft proofing in Adobe RGB. I can't see any difference between soft proofing in Adobe RGB and normal (soft proofing off), but then my monitor goes only slightly beyond Adobe RGB for yellow/orange colours so I might not see it.

JoachimStrobel said:

Click to expand...

--
Simon

Simon,

I set my profile to AdobeRGB and start LRc. I go to Develop-Softproof. Now there is a initialy greyed out button "Simulate Paper and Ink" that becomes usable once a CMY profile is selected in "profile" and then in changes the image to what it would look like on paper.

I can select a screen profile too, like sRGB. But that will not change the image from AdobeRGB (what I set my icc profile to and the monitor´s gamut) to sRGB. There is no single change in that Image. Which makes sence, as the label says "Simulate paper&ink" and not "screen".

I have set up a side-by side display within the Sw270, using another port on my graphics card and selected AdobeRGB for the right and sRGB icc profile for the left side together with the correct sub-monitor settings. When I now move the LRc window from the AdobeRGB side to the sRGB side, the image will change when it is 100% within the sRGB side. And the changes are clear and show what the red shading indicated. (That can be done with any two-monitor setup, but one would need two identical monitors with identical calibrations to be sure about the observed change)

I tried to trick Lr by copying an sRGB icc profile into the paper icc section and selected that as "paper" icc, hoping that LRc would then change the image as it does for a CMY profiles - it did not .

JoachimStrobel said:

Simon,

I set my profile to AdobeRGB and start LRc.

Click to expand...

Just checking: you mean the monitor is set to Adobe RGB mode (either the factory preset or one of the user calibration slots calibrated to Adobe RGB) with a corresponding profile set as the Windows default monitor profile)?

JoachimStrobel said:

I go to Develop-Softproof. Now there is a initialy greyed out button "Simulate Paper and Ink" that becomes usable once a CMY profile is selected in "profile" and then in changes the image to what it would look like on paper.

I can select a screen profile too, like sRGB. But that will not change the image from AdobeRGB (what I set my icc profile to and the monitor´s gamut) to sRGB. There is no single change in that Image. Which makes sence, as the label says "Simulate paper&ink" and not "screen".

Click to expand...

If the monitor is calibrated to Adobe RGB (with a corresponding monitor profile) and you soft proof and select sRGB then the image won't change - except for any pixels with colours outside sRGB, such as the orange colours in a sunset. Those will be clipped.

JoachimStrobel said:

I have set up a side-by side display within the Sw270, using another port on my graphics card and selected AdobeRGB for the right and sRGB icc profile for the left side together with the correct sub-monitor settings. When I now move the LRc window from the AdobeRGB side to the sRGB side, the image will change when it is 100% within the sRGB side.

Click to expand...

For give me, but I don't understand what you are saying. I can't comment on side-by-side working as I don't think my SW271 has that, and I don't know exactly what that does in terms of calibration.

However, you say this is the same as having multiple monitors, one wide-gamut and one sRGB. When you move the Lightroom main window from one monitor calibrated and profiled to Adobe RGB to another monitor calibrated and profiled to sRGB, the image should not change - except for pixels with saturated colours outside sRGB. If it does change, then there is an issue with colour management, such as the Windows profile not matching the current monitor calibration, or LR not using the current profile.

One thing you need to be aware of: if you change the calibration and profile of a monitor while LR is running, then it won't notice and will continue to use the previous profile. You have to exit and restart LR before it will notice any change in profile.

Turning soft proofing (to sRGB) on and off won't show any change in the image on an sRGB monitor. That's just switching from sRGB to sRGB. But it will show a change on a wide-gamut monitor.

I'm not sure what I'm missing about what you are saying.

JoachimStrobel said:

And the changes are clear and show what the red shading indicated. (That can be done with any two-monitor setup, but one would need two identical monitors with identical calibrations to be sure about the observed change)

I tried to trick Lr by copying an sRGB icc profile into the paper icc section and selected that as "paper" icc, hoping that LRc would then change the image as it does for a CMY profiles - it did not .

Click to expand...

Simon,

thanks for your comment which help me a lot reflecting on what I am doing.

I guess we have to leave the misunderstanding as is and/or would need some kind of Team meeting to resolve that. But let me try again:

My photo shows out of gamut sRGB colors. Viewing it on my AdobeRGB Sw270 monitor utilizing an AdobeRGB icc profile I see nice color shadings in the said dark blue. LR will flag those as being out of gamut for sRGB, but will not transpose them for sRGB within my AdobeRGB gamut display. Moving the LR Window onto the other half of my SW270, emulating a true sRGB display on that side (I could add screenshots how to do that if needed) shrinks the colorspace, and I can observe how the shades of blue get lesser and the blue becomes a bit different. Not a large change, rather subtle, like MP3 vs 44/16. LR learnt during startup, that there are two monitors, with different icc profiles, I am not changing them later.

The Sw271 can do that too, the BenQ website calls it GamutDuo. It needs a real second port on the graphics card connected to the monitor.

JoachimStrobel said:

Simon,

thanks for your comment which help me a lot reflecting on what I am doing.

I guess we have to leave the misunderstanding as is and/or would need some kind of Team meeting to resolve that. But let me try again:

My photo shows out of gamut sRGB colors. Viewing it on my AdobeRGB Sw270 monitor utilizing an AdobeRGB icc profile I see nice color shadings in the said dark blue. LR will flag those as being out of gamut for sRGB, but will not transpose them for sRGB within my AdobeRGB gamut display. Moving the LR Window onto the other half of my SW270, emulating a true sRGB display on that side (I could add screenshots how to do that if needed) shrinks the colorspace, and I can observe how the shades of blue get lesser and the blue becomes a bit different. Not a large change, rather subtle, like MP3 vs 44/16. LR learnt during startup, that there are two monitors, with different icc profiles, I am not changing them later.

Click to expand...

Thanks for that explanation, although I still would not expect any change in appearance moving the LR window from an Adobe RGB colour space screen to an sRGB colour space screen, except that colour out of gamut in sRGB would be clipped to the nearest equivalent within sRGB on the sRGB screen. One difference might be with perceptual intent, where in-gamut colours as well as out-of-gamut colours can change slightly when an image is rendered to a smaller colour space. I tried a few sample pictures of mine, and even choosing perceptual intent made no difference except to out of gamut colours.

With paper profiles, checking "Simulate Paper & Ink" does make a difference to all colours - not just out of out of gamut colours - as (I think) it's simulating the contrast range as well as colour gamut. Also there is a slight difference between relative and perceptual intent.

Anyway, thanks again for the detailed explanation. I'm not for a minute doubting what you describe, just I don't understand why there's a difference. One of life's great mysteries!

JoachimStrobel said:

The Sw271 can do that too, the BenQ website calls it GamutDuo. It needs a real second port on the graphics card connected to the monitor.

Click to expand...

Thanks! I hadn't noticed. In my manual it's described as "PBP" - which seems to be "Picture Beside Picture". As it's dealt with alongside PIP, for which I don't have much use, I hadn't seen it.