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Background: I just bought a USB-monitor to use on the road with my Macbook Pro, Asus MB169+. It sends both power and signal through a single USB3-cord. There is no way to set the brightness, contrast, or indeed anything but the backlight.
Question: I made a profile, which works very well (unexpectedly well actually) except it clips in the red and green channels. Without any controls, is there a way to limit those channels to fit in the monitor gamut? Either before calibrating, or perhaps edit the profile itself?
If helpful in any way, I attached the profile I made.
Thank you for this amazing calibration suit!
/StaffanThe gamut of this monitor is considerably smaller than Rec709/sRGB, that’s why you see clipping (sRGB is about the smallest and most common source colorspace). If you enable advanced options in the “Options” menu, you can create a CIECAM02 perceptual mapping by clicking on the “gear” icon on the “Profiling” tab and checking the respective box, then using “Create profile from measurement data…” (again in the options menu) to re-generate the profile. This will compress the source gamut (by default sRGB) to fit within the display gamut.
Thank you! I’m not by the calibration device at the moment, so it’s hard to understand exactly, but does the CIECAM02 perceptual mapping involve a separate profiling run?
Also, my guess is that Asus have applied a very hard response curve to the monitor to make it look brighter. Would it be of any use to profile with a linear ICC-profile installed? The monitor reacts weirdly to profiles, and using the built in MacOS profiler isn’t possible as it isn’t reacting to changes. This is a limitation of the USB driver.
Thanks,
/Staffandoes the CIECAM02 perceptual mapping involve a separate profiling run?
No, you can just re-create the profile from the existing one, no measurements required.
Would it be of any use to profile with a linear ICC-profile installed?
Profiles are inactive during measurements anyway.
does the CIECAM02 perceptual mapping involve a separate profiling run?
No, you can just re-create the profile from the existing one, no measurements required.
OK, I’ll try that. Thank you very much!
Would it be of any use to profile with a linear ICC-profile installed?
Profiles are inactive during measurements anyway.
Well, the thing is; DisplayCAL, or any other program for that matter, can disable the current profile… the profile stays in Safari windows until reloaded etc… it’s a weird monitor.
Thanks,
/StaffanThe gamut of this monitor is considerably smaller than Rec709/sRGB, that’s why you see clipping (sRGB is about the smallest and most common source colorspace). If you enable advanced options in the “Options” menu, you can create a CIECAM02 perceptual mapping by clicking on the “gear” icon on the “Profiling” tab and checking the respective box, then using “Create profile from measurement data…” (again in the options menu) to re-generate the profile. This will compress the source gamut (by default sRGB) to fit within the display gamut.
Do I have to use the “CIECAM02 perceptual mapping” too?
Do I have to use the “CIECAM02 perceptual mapping” too?
Depends on what your goal is. Your monitor gamut looks larger than sRGB, but if you’re aiming to edit AdobeRGB photos, you may benefit from a perceptual table that compresses AdobeRGB into your display gamut.
Do I have to use the “CIECAM02 perceptual mapping” too?
Depends on what your goal is. Your monitor gamut looks larger than sRGB, but if you’re aiming to edit AdobeRGB photos, you may benefit from a perceptual table that compresses AdobeRGB into your display gamut.
I’m ok then, I don’t have any special needs for AdobeRGB, thank you for the answer 🙂
I tried to re-generate the profile, but I get an error message and it says no profile could be made. It does generate a profile, but it has very (very) washed out colours.
Any ideas?
Regards
/StaffanThe problem with this monitor is that it has a “dead” region near white (and to a lesser extent near black) where an increase in RGB levels does not lead to a change in luminance. This is a problem. Does the monitor have any dynamic contrast/dimming features? If so, they need to be turned off during measurements. It could also be that the signal the graphic card sends is full range RGB (0..255) while the monitor expects video range (16..235).
Anything is possible, the monitor sends its signal through a single USB-cable. It relies on a Displaylink driver to work. The signal is somehow compressed, to be able to run on the USB bus. It’s not possible to turn the profile off, or I haven’t found a way to do so anyway. DisplayCal doesn’t disable the profile while measuring. The compression could be the culprit.
Now I am unable to make a profile at all. I get the same error as above every time. Weird thing is, it worked a couple of days ago, and produced a profile that is almost acceptable for my purposes, except the loss of very bright colours. I didn’t record my settings, but it worked both with the original ICC-profile active, and also with a sRGB Gamma 1. Now nothing works…
Thank you for a great product, and great support! Very worthy of donations I think. Thank you!
/StaffanOh, also, the monitor doesn’t have a dimming feature that I know about. The only control is for the LED backlight.
I managed to make a profile that actually works pretty well. I hadn’t picked a source file under the gear icon. I still get a warning that says it couldn’t make a profile, but it still works.
There is some green tint in some grey areas that wasn’t there before, but the highlights have improved much. I attached the profile, but I don’t know if there is anything I can do to fix it?
Thank you so much for your help, I will encourage people to use DisplayCal.
/StaffanI attached the profile, but I don’t know if there is anything I can do to fix it?
You may be able to work-around the display’s “dead” regions near white and black, but you need to run a new calibration + profile. Important: Don’t change the monitor’s backlight from what it was for the previous profile. On the “Calibration” tab, set black level to “Custom” (don’t enter a value, leave the default), and set white level to 75 cd/m2. That should limit the channels via the calibration curves, leaving out the problematic regions.
