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hi there,
Tinkering with my monitors I’ve come across something I’d like to better understand.
I found that my i1 display pro was coming up with some pinkish whites on my new laptop so I thought I just needed to profile the probe with a spectrophotometer, which I have access to.
Long story cut short, I put the “Visual whitepoint editor” on my main monitor (CCFL, MVA) and on my laptop monitor (LED, IPS). I manually dialed the perfect rec709 colour coordinates and similar brightness on both (my laptop doesn’t go higher than this and my monitor lower than this!) and I end up with a pinkish white on my laptop.
This is a Colorimetry Research CR-300. My I1 Display reads very similar values, it’s not too far away.
Now, I appreciate that different spectrum take to different subjective results – and the spectrum are indeed quite different.
But I was not expecting such a difference. If a spectrophotometer cannot account for those differences, what is the point of calibrating the white point? Isn’t there a better, more reliable way to assess the white point of a display?
If I try and take a picture of the screens – on the same frame – the tint does not show up.
I am attaching the results. I’d appreciate your opinion – I’m not necessarily trying to fix this, I just need to understand this!!
Thanks
Calibrite Display Pro HL on Amazon
Disclosure: As an Amazon Associate I earn from qualifying purchases.See the FAQ entry on visual whitepoint mismatch and metameric failure. Flanders Scientific also have a really good video on the topic:
That is incredibly interesting. I knew about metamerism but I thought it would only apply for massively different spectrum – such as Laser RGB. I had no idea that a ‘pickier’ spectrum such as the one shown on my laptop could also cause a metameric failure.
While I do agree with you that calibration and profiling is still useful as it would make sure that all is perfectly matched to the chosen white point, how should you calibrate a display that clearly shows a tint at D65 if you do not have a better reference handy?
I knew about metamerism but I thought it would only apply for massively different spectrum – such as Laser RGB
I would call the spectra you posted above quite substantially different (both look typical for their respective technologies though, with the CFFL one being peakier and the white LED one being somewhat smoother).
ow should you calibrate a display that clearly shows a tint at D65 if you do not have a better reference handy?
Pick either of your displays as reference, then adjust the other one to match.
thanks. I thought the metamerism only applied when the spectra were much more different, that’s it. Half of my professional knowledge is sound and in sound the acoustic is always there to make things more complicated as microphones will pick up reflections as well and they are time-blind. I’ve always told people “sound is not like colours: what the colour meter says cannot be disputed”. I was totally wrong.
You say I can take the one that does not look tinted as reference. What if I do not have a reference? Say I calibrate my only monitor and it looks pinkish at the end, do I just decide by eye what is the correct white point? Maybe the ambient light is bluish, so my eyes are biased by it and I end up choosing the wrong white.
I have the perfect example in front of me: this time I decided not to tweak the white point via projector controls. As such, white is pretty greenish with no calibration. If I use my computer with no calibration for 10 minutes and then enable the calibration, the picture is obviously reddish for a good while – while your eyes adapt.
What I am trying to understand is: how come there isn’t a way to better simulate human eyes using a tool? What is the point of setting up a perfect white point on a monitor if we don’t know if the spectrum is ‘one of those’ which will give me the ‘wrong’ result?
I mean, what happens in the professional world? How are those monitors calibrated?
Thanks
I’ve got some of the answers after watching the video you linked, thanks. Again, very interesting subject.
It’s a matter of ongoing research. But truthfully, absolute white accuracy simply often doesn’t matter as much as people may think it does, and the reason for that is the way the human visual system works (we can adapt to a quite wide range of “white” light) and observer variability which makes any attempt to establish a true absolute white standard challenging if not impossible – because what may look like a match to one person may not to another (but the relation of colors to white will still be perceived similarly, which is the important point). What matters much more is consistency (i.e. the calibrated white should look the same on all monitors that are viewed together, and the surroundings and ambient lighting, if any, should not have an apparent different hue). But one should not worry too much that the calibrated white throughout facility A may not match that of facility B (or that of the end user/viewer).
Indeed, that seems to be the way to go.
What is the point of profiling colour meters then if the white point is going to be inaccurate anyway?
In the end you are saying that when I am calibrating a display and I don’t have a reference with me (referenced to what then?) my role would be to make sure the calibrated white on that display does not show an obvious hue. Which is a difficult task as, as you say, our eyes can adapt to the existing white point.
What is the point of profiling colour meters then if the white point is going to be inaccurate anyway?
It still can help to match an instrument to one of higher accuracy (e.g. colorimeter to spectrometer), i.e. in some situations that could be all that is needed to produce a metameric whitepoint match.
