Yellow tinge from bottom to top of the screen, 27" iMac

I do get it dino, but I am just laughing my way all the way to the day you guys here would be writing, and complaining about what apple is not selling, which is the ultimate display, not only that dino you got a free upgrade from a 21.5 inch display, and apple was nice enough to upgrade you to a 27 inch display.
For all of you insisting that you think your going to get a perfect display, keep on dreaming for the next couple of years. I don't want to sound harsh, the reality is, suck it up and live it, if not return the iMac, get your 15 percent for your troubles and buy a dell, see if you think your going to get the ultimate display there. I doubt that dell would be even any better, why hang to the machine, lets be honest, really, you think apple is going to fix the problem, I doubt it big time.
I am wondering why they are having some people replace their machine up to 3 times, I am guessing they are playing baseball, 3 strikes and your out, haahaahaahaah. Well for all of you with yellow mellow, iLemon, get a refund, I think its my best advice.
Stop stressing your body with this issue because its not healty for you nor for your pocket and time, really I would of gotten a refund, and go to gateway or dell.

andraki01 wrote:
Pixel crunch?
21.5 imac is a standard 1920 x 1080 and the one I owned had the worst case of yellow I have ever seen!

Bottom line is - If one spends £1634.00p on something that is advertised has having the "ultimate display" One should expect it to be "ultimate"

Slightly off topic, but you don't see everyone driving a BMW do you? Despite them advertising it as the ultimate driving machine.

If some Chinese car company starts claiming their car is the ultimate car, would you go buy it??

Bottom line is, Apple did not force anyone to buy anything from them. They sell the product as is w/ certain terms and conditions. Make an informed decision and buy it if the product is what you are looking for. Otherwise, move on, and buy a Dell, HP, Acer, Asus, MSI etc. No one is twisting your arm to buy a yellow iMac.

Stop beating on a dead horse.

Today I took my 27" i7 to the "Geniuses" at Apple for a replacement display. I was informed that the display was one of the "new ones" with a new part number. The folks at the Apple store claimed to have put the machine through rigorous testing before replacing the display and found nothing wrong. That tells me they are totally clueless since the only test needed is a pair of eyes and the grey bars or a colorimeter, not some software diagnostic! After pushing them to replace the display as was the plan based on my discussion with AppleCare customer relations, they went ahead and did so. I was shown the new display in a brightly lit Apple Store so it was quite difficult to tell if the issue was resolved.

I took my iMac home and allowed it to warm up for an hour before doing my own tests. I used a Datacolor Spyder3 Elite colorimeter to test the color temperature uniformity of the new display. A test area of a light neutral grey was used (almost white). I measured the color temperature of this test area in 4 quadrants: left upper, left lower, right upper, and right lower.
The results are as follows: left upper=6708K, left lower=6555K, right upper=6331K, right lower=6134K

The difference between the left upper and the right lower is 8.5%. That amount of variation doesn't seem right to me. What do the rest of you think? At this point I am fed up and will probably ask for my money back and wait until the next generation of "ultimate displays" to see if they are able to truly re-engineer them. I am sick of the lies I've been hearing from Apple about how they have resolved the issue.

Your right there is a problem with these iMac screen, is apple going to fix the problem, I don't think so that ultimate display is not going to get fix nor this year or any years to come, the probelm is most likely on the backlit or in the diffusers. Is LG going to fix the problem, maybe, but my advice is if you got a yellow ting and cannot live with it, get a refund stop torturing yourself with the fact that apple may come with a fix in the following weeks, because they are not the manufactures of the ultimate display.
As of now I am going to Mcdonalds, there burgers look mighty tasty in those photos, oh man to my surprise the big mac doesn't look like in the picture, I am returning this burger now.
Same thing goes with this iMac, apple is not selling you the ultimate display well get a refund, sorry that you are being lure for bad advertisment.

mstrammd wrote:
The results are as follows: left upper=6708K, left lower=6555K, right upper=6331K, right lower=6134K

The difference between the left upper and the right lower is 8.5%. That amount of variation doesn't seem right to me. What do the rest of you think?

Hi mstrammd,
I did exactly the same test with the same tool (Spyder 3 Elite) on my unit.
The white point is at 6500 Kelvin.
So you have only a difference of 200K upward (almost normal) and 400K downward (=6.1%, not so bad).
Looking at your figures, it could be difficult to find a better one, but very easy to get a worst one.

Cheers,
Jacques.

Jacques LAPORTE wrote:

mstrammd wrote:
The results are as follows: left upper=6708K, left lower=6555K, right upper=6331K, right lower=6134K

The difference between the left upper and the right lower is 8.5%. That amount of variation doesn't seem right to me. What do the rest of you think?

Hi mstrammd,
I did exactly the same test with the same tool (Spyder 3 Elite) on my unit.
The white point is at 6500 Kelvin.
So you have only a difference of 200K upward (almost normal) and 400K downward (=6.1%, not so bad).
Looking at your figures, it could be difficult to find a better one, but very easy to get a worst one.

Cheers,
Jacques.

Hi Guys,

Could you tell me how do you do that test? Do you first take a photo of the screen with a camera and do the analysis to that image or are you using a physical tool to measure the display?

Cheers!

Hey fa_design,

Take a look here :

http://www.northlight-images.co.uk/reviews/profiling/spyder3elite.html

The Spyder 3 is a tool with a sensor and it measures light externally from the monitor (LCD or CRT).

Cheers!

ps: I don't know if you read French, but here is another link, with the price I paid.
http://www.missnumerique.com/traitement-de-l-image-sonde-de-calibration/colorvis ion/colorvision-datacolor-sonde-de-calibration-spyder-3-elite-p-3122.html

All right! thanks mate. I guess that's similar to the Pantone Huey but more accurate:
http://www.pantone.com/pages/products/product.aspx?pid=79

It's an expensive tool but very practical for calibrating.

Merci!

Hi Jacques,

What I would like to know is what is considered to be an acceptable industry standard for non-uniform white balance in an LCD monitor. What is acceptable in a good monitor? I have posed this question to the folks at Datacolor to see what they think. I would have thought that a +/-1 to 2% from 6500K would be an acceptable tolerance in a good monitor, but I'm no engineer.

Furthermore, these differences are clearly visible to the naked eye. I think that is unacceptable. I will be contacting Apple again. If they are not willing to rectify this, then I will get my money refunded and wait for the next generation iMac. I will go back to using my C2D iMac as my main machine even though it has way less capability than the i7.

Hi mstrammd,

I'm not saying that there is no problem with this new LED backlight technology.
I think -on the contrary- they probably have a thermal problem.

A tolerance of +/- 2% from 6500K would be, IMHO, very hard to achieve on those wide new panels.
The mean of your 'upper' measures is (6708+6331)/2 = 6519 Kelvin : close to normal.
The lower mean is 6344K which is warmer than the white point.

In fact, it seems you have a right lower corner warmer (like on my unit ; 6500K on top, 6100K bottom ).

I am not aware of de facto "acceptable industry standard" for this kind of defect.
Try to calibrate it pushing the white point around 6750K and see if you can stand it.

But there is no miracle, less 'pinkish' at the bottom more 'icy blue' at the top.

I understand your disappointment.
Best of luck.
Jacques.

PS : I found this link interesting : it presents a methodology for LCD monitors testting.
This page 4
http://www.xbitlabs.com/articles/monitors/display/lcd-testmethods_4.html
is about brightness uniformity for white and black or different colors.
There are data to make comparisons.

"For the sake of quantitative comparison between different monitor models we always provide percentage values in the text of the review: average deviation and maximum deviation. At first we calculate the arithmetic mean of the screen brightness and then find the average and maximum deviations.

*Speaking of particular numbers*, if the deviation is within 5% it is considered a good result, within 7-8% - acceptable, and over 8% poor. As for the maximum deviation, the range is more lenient: if it doesn’t exceed 15% - good, 20% - acceptable, over 20% - poor."

Yes slightly off topic.

Sold as is? Where does it say in the terms & conditions "display may have a grey horizontal bar along the screen, or it may flicker, or it may display a yellow vomit effect" ?

I can spend £129 on a HP 23" monitor which exhibits none of these defects!

I have a question for the group. I have been waiting for months to purchase a 27" iMac. It is important to me that the display be of very good quality. What with the continuing issues relating to yellow tinge and grey bands, I am wondering if I might be better off picking up a refurbished mid-range Mac Pro and buy the 24" Apple LCD to complement it instead of the iMac. The higher cost and greater energy utilization might be offset by greater flexibility. Any thoughts on whether I would be more likely to have a better display? The tower would go under the desk in this instance. Thanks.

So just before Apple had a chance to send out another refurb to replace my limited edition yellow screen iMac I called them and asked for a refund. Based on what I'm reading, the chances of me getting another dud are pretty high and I'm not very keen on repeating the whole exchange process.

I'll be making a trip to our local Apple stores and seeing the units in person. If all else fails I'll have to wait for the next revision.