I've seen some of your posts, Atomic Walrus, and you seem to know what you're talking about. So can you help me understand; why is Apple giving people these yellow displays? I know they're not all yellow because my first one wasn't yellow. Then I needed a replacement and my second and third ones were yellow on my 2012 15" Retina MacBook Pro. Why? Apple claims they are normal when I complain. Are they normal? I bought a Spyder4Elite and it helped reduce the yellowness a little bit but the colours are still muddy and unnatural. What's going on?
The short answer is probably that it's not easy to make these panels. If these yellow displays are considered within spec, imagine the ones that didn't make the cut. If we could see the yield rates I'd have to assume it's considered impressive just to get a relatively uniform 15.4" 2880x1800 panel that's within ~700 units of the target white temp.
I think Apple partially created this situation by asking for the production of 6500K displays (remember the early iPhone displays which were really blue, before Apple got serious about calibrated panels?). 6500K is a warmer white than people who've used cheaper, uncalibrated displays are used to seeing. Most display manufacturers will aim for a much cooler white because it convinces the user that their display is brighter or more vivid.
Aiming cooler also allows a greater tolerance for screens coming out too warm without appearing yellow, which is aesthetically unpleasant:
A combination of a 6500K target and wide manufacturing tolerances due to the pixel density of the displays leaves us with panels that might range from (just making up some numbers) 5800K to 7200K. The panels all the way down below 6000 are going to look really yellow, but the displays up around 7000 will just look "more white" to the average user so they never get reported as defective (no one without a meter is going to return their computer for having whites that are "too white").
The question is why Apple doesn't demand better quality, and I'd say it's because at the moment their hands are tied; they can either buy Samsung's yellow panels, take their chances with LG's IR, or stop making rMBPs until Sharp can supply them with IGZO panels in the resolutions they want. Samsung's not a good company for Apple to be doing business with at this point (Apple clearly knows this) because of their direct rivalry in the same product spaces. To get conspiratorial for a moment, If you're Samsung would you potentially keep your best panel material for the products you manufacture instead of selling it to your directly rival?
If we check out Anandtech's iPad Air review we see that the sample he got was actually right at that upper number (about 7200K). If we assume Apple is still targeting 6500K and hasn't bumped the target temperature a bit cooler to get away from the yellow then there could be 5800K iPads out there that would look quite yellow.
Personally I'd happily pay more to get away from this temperature lottery thing, but Apple's sales numbers suggest that people are generally pretty happy with the results.
6500K will appear yellow compared to many displays in their factory settings.
You're right, and I'm sure that complicates this discussion since people who actually have 6500K panels are jumping on the yellow screen train, however a lot of these panels are well below 6500K (and it seems like more Samsung panels are below than above).
I have a professionally-calibrated Kuro here (it's been a while but it shouldn't have drifted too far) which happens to match up pretty well with my Apple Cinema Display (and an iPhone 5s). Meanwhile the rMBP looks old-paper yellow when compared with all three. An eyeballed adjustment of the white point would suggest it has a native white in the neighborhood of 5900K. Maybe that's within tolerances (it shouldn't be, but that's an issue to take up with Samsung and LG), but if so they need to increase the target point.
Most users aren't concerned with perfect color accuracy for precision image work. Those who are will need to calibrate anyway. What the average user is going to notice is that their screen looks like it has tobacco stains and that calibrating it out reduces their contrast. If Apple can't get these guys to lock down that range they need to move the target up to like 6800K just to avoid the pee-yellow displays.
The uniformity is another issue, and not one you can calibrate your way out of. Some of these panels are like 6900 on one side, 6100 on the other. I guess that might just be the state of consumer IPS.
Actually I probably could have just said that one sentence and avoided writing the whole mess above; uniformity issues and a wide temperature range define the state of high-density display manufacturing at the moment. I hope Apple is doing whatever they can to push for higher quality.
