Just got 24" iMac! But I'm concerned about...

[czachorski]

You can continue to defend it all you want and the odds would be what you wrote if those were the percentages of faulty displays (I did not need your explanations btw on statistics, I did a lot of university level statistics ... ), the reality is still that all displays I have seen in all stores I went to had the problems which is far and beyond what the odds would be with your numbers. The only reason you don't have more people complaining is because people either don't care or don't see it, plain and simple and good for them. I am out.

My experience at stores has been just the opposite. All are good. Others have told of stores with all bad ones too. It could be a bad batch, a store set-up from early ones when the problem was more prevalent, or a freak of stats.

If they were all bad, there wouldn't be a 9 page thread here (with photos) of people with good ones.

If they were all bad, then there wouldn't be any stores at all with good ones (not 3 stores in my area with all good ones).

If they were all bad, there would be a lot more complaints here and otherwise.

But to insinuate that they are all bad and people don't notice is absurd. The ones I have seen that are bad are really bad. Ugly yellowish tints and significant brightness drop off. Are you telling me someone would not notice something like that, or tolerate it? On a $2,000 computer? Ya right.

 

[jvette]

I got my Imac 24" 2.8 2mg on Wednesday from the local Apple Store and so far I can't find one ounce of problems with the screen. It's perfect! So is the whole computer. I did a couple of tests suggested on here.

 

[MacNerd12]

I am shocked at some of the problems people are having with their Aluminum iMacs. I've had mine for close to if not more than 5 days and I have had not one single problem with it. It's been running from about 6:30 AM until around 1AM the next morning since I got it on X-Mas eve.

 

[imacspert]

Ok, so show us a pic of a 'good' screen please..

My experience at stores has been just the opposite. All are good. Others have told of stores with all bad ones too. It could be a bad batch, a store set-up from early ones when the problem was more prevalent, or a freak of stats.

If they were all bad, there wouldn't be a 9 page thread here (with photos) of people with good ones.

If they were all bad, then there wouldn't be any stores at all with good ones (not 3 stores in my area with all good ones).

If they were all bad, there would be a lot more complaints here and otherwise.

But to insinuate that they are all bad and people don't notice is absurd. The ones I have seen that are bad are really bad. Ugly yellowish tints and significant brightness drop off. Are you telling me someone would not notice something like that, or tolerate it? On a $2,000 computer? Ya right.

Do you or does anyone else mind posting a pic of a 'good' screen? Thx.

 

[vansouza]

Do you or does anyone else mind posting a pic of a 'good' screen? Thx.

We have been through this ... search the forum and you will find what you are looking for. Good luck.

 

[czachorski]

Do you or does anyone else mind posting a pic of a 'good' screen? Thx.

See this thread for an exhaustingly thorough discussion of the issue. As posted in that thread, here is mine:

Almost everyone who is getting them now reports this level of performance. That thread is 9 pages long and still going with good screens. The number of threads with bad ones has tailed way back, but still there is one occasionally.

 

[imacspert]

See this thread for an exhaustingly thorough discussion of the issue. As posted in that thread, here is mine:

Almost everyone who is getting them now reports this level of performance. That thread is 9 pages long and still going with good screens. The number of threads with bad ones has tailed way back, but still there is one occasionally.

I don't mean to doubt that your screen is indeed perfect, but from this picture your screen seems a bit brighter on the left side vs. the right. This is exactly what I saw with my screen. I'm wondering whether I exchanged it for no reason. I did not really see any severe yellowing but did notice a difference in brightness between each side of the screen.

Well, in any case, thanks everybody for your input. Great resource here. I will report back what I find with my new iMac.

 

[Rustman]

I've got the gradient issue with the display on my iMac 24" Alu too. But it isn't that bad. At least, not in the middle of the screen where I look most of the time.

For colour sensitive work I intend to plug in my Dell 2407, should I need that.

The gradient issue and the yellowing is nowhere NEAR as bad as the Macbook Pro that I sent back two weeks back.

I'm a graphic designer by trade, consider myself to be very picky about my electronic purchases, but despite this issue I've still retired my PC and I'm using my new iMac all the time now.

I can sympathise with the OP, but I've relaxed my expectations slightly. Apart from the slight yellowing, I'm pretty happy with my decision.

 

[HLdan]

try going here: http://www.lagom.nl/lcd-test/#angleGrey

then make your web browser smaller, so you can move it around your screen, and see if you can see the lagom text changing in comparison to the background? then let me know....

See this is precisely my point. If you have to go there and look at specific screen shades just to see a slight unevenness then what's the point? If your screen is really bad you will have trouble viewing it with any background and at the point then you will need to call attention to Apple.
I cannot count how many pairs of shoes I have purchased where one shoe fit perfect and the other felt smaller and sometimes I get a pair that fits near perfectly, so my point is don't look for perfection you will make yourself crazy.
It's Apple's beautiful aesthetics that make people look for imperfections.
Ask yourself would you truly pick a Dell machine apart like this? My guess is probably not.

 

[czachorski]

I don't mean to doubt that your screen is indeed perfect, but from this picture your screen seems a bit brighter on the left side vs. the right. This is exactly what I saw with my screen. I'm wondering whether I exchanged it for no reason. I did not really see any severe yellowing but did notice a difference in brightness between each side of the screen.

Well, in any case, thanks everybody for your input. Great resource here. I will report back what I find with my new iMac.

Perfect is a dangerous word. I doubt you will find any "perfect" LCD screens. If you were to get a light meter on it, or perform a photoshop analysis on it, you might find a few percentages variation. So no, not perfect. The "gradient issue" that has plagued some iMacs has been as much as a 2.5x variation in brightness from left to right. If you get one like that, return it. This is the point being made here: not all iMacs have this defect. In fact, very few do. Most iMacs, and most LCDs are going to have some very slight uniformity variations. These are perfectly normal, not noticeable during normal usage and may only be notices with a light meter or working with photoshop on a photo of the screen to see it. I will submit that if that is the case, and the only way you can see it is with such ridiculous scrutiny, then it is not defective.

For instance, here is that same photo of mine photoshopped to put the left and right edges next to each others:

Are you going to tell me that such a gradient should be considered defective?!? If so, I think this is a case of unreasonable expectations, and I would expect that you are not going to be happy with most LCDs. So define defective! If you have to photoshop it or analyze it with a light meter to find a flaw, I would question whether that is defective. If it has a 2.5x brightness gradient that anyone who looks at it sees, that is clearly defective. I know for a fact that not all iMacs have the 2.5x brightness gradient, and I bet that all of the have a few percentage points of brightness non-uniformity. I think it is important to have reasonable expectations about LCD quality, iMac or other, in mind when making such a purchase.

By the way, many have claimed that the old white iMacs had better screens, and that this gradient issue was something that Apple did wrong with the Alum iMac. One of the big contenders of this theory posted his "perfect" white iMac screen photo, and here is a link to the full photo, and here is the left and right edges:

That is a gradient that jumps out at me, and its from a white iMac. I have even done similar tests with my Apple Cinema Display that I have used and thought was perfect for 2 years, and can see a slight gradient when photographing it and photoshopping the edges together.

If you want to drive yourself nuts with this, go ahead. It's an easy thing to do.

 

[imacspert]

What I'm trying to do is understand what the threshold is for the gradient issue vs. what's normal for an LCD screen. That's it. This isn't about unrealistic expectations (at least not in my case).

It's about spending $2K and ensuring your display works as it should. I think that's what everyone is trying to do. In my case, I didnt notice the gradient issue until i tested for it, but after that everytime I had two safari pages I could see a slight difference in the intensity of light between the left and right sides.

If that's normal, then great..I'll be happy with my machine.

 

[Cloudane]

lol denial

My 20" has a gradient (top-down gamma)
The 20" I saw in PC world has a gradient
The 24" I saw in PC world has the slightly different 24" gradient (left-right yellow/purple)

The 20" one is a characteristic of TN panels. Others I've used have the same issue.

The 24" one I don't know, but on the one I saw in PCW it was barely noticable and I'd never had noticed it if nobody had said about it here. It did exist though.


Regarding the sound, is this under Windows? Upgrading to the latest Realtek drivers alleviates the issue somewhat. It's still there but much less noticeable.

 

[czachorski]

In my case, I didnt notice the gradient issue until i tested for it, but after that everytime I had two safari pages I could see a slight difference in the intensity of light between the left and right sides.

It's going to be difficult to diagnose what you are describing as normal or defective without seeing it. Earlier you referenced my photo and referenced seeing a slight gradient. If that is the level you are looking at, and knowing my screen, I would have a hard time keeping a straight face while trying to explain to an Apple employee what was defective about it. The gradient in the photo is barely noticeable in photoshop when placing the right and left edges next to each other. That doesn't seem like strong enough evidence to me to pass muster to warrant an exchange.

On the flip side, if everyone who walks in the room immediately looks at it and says - "ewwwww, what's wrong with your computer", then it is obviously a dud.

It sounds like what you have got is that huge gaping grey area. It's your call. Because of the challenges of describing it, or challenges of photographing it (the flaws of which have been discussed on other threads), you might be best off asking a few people around you to look at it for an objective view. If you have to explain to them what to do in order to notice the defect, you might start to feel better that there is an element of over-scrutiny and not an issue to the level of defective. If they see it without coaching, then you know it is a problem.

As I said earlier it's easy to torture yourself over such a thing.

 

[imacspert]

It's going to be difficult to diagnose what you are describing as normal or defective without seeing it. Earlier you referenced my photo and referenced seeing a slight gradient. If that is the level you are looking at, and knowing my screen, I would have a hard time keeping a straight face while trying to explain to an Apple employee what was defective about it. The gradient in the photo is barely noticeable in photoshop when placing the right and left edges next to each other. That doesn't seem like strong enough evidence to me to pass muster to warrant an exchange.

On the flip side, if everyone who walks in the room immediately looks at it and says - "ewwwww, what's wrong with your computer", then it is obviously a dud.

It sounds like what you have got is that huge gaping grey area. It's your call. Because of the challenges of describing it, or challenges of photographing it (the flaws of which have been discussed on other threads), you might be best off asking a few people around you to look at it for an objective view. If you have to explain to them what to do in order to notice the defect, you might start to feel better that there is an element of over-scrutiny and not an issue to the level of defective. If they see it without coaching, then you know it is a problem.

As I said earlier it's easy to torture yourself over such a thing.

Very true. I will try that on this next iMac (hopefully gets here tomorrow) and go from there. Wish me luck!

 

[czachorski]

Just to illustrate how you can drive yourself nuts with this, take a look at this. You said that the photo I posted is "exactly what I saw with my screen." When I look at the photoshop of the left and right next to each other, the right does indeed look a little darker than the left. Is it real? Or is it caused by the blue scroll bar? Here is the original photoshop of the edges, and then two versions of the same image rotated 180 degrees that have been cropped to eliminate the blue bar. Can you tell which side is the "darker side" now?

This just goes to show that there are so many items that can cause you to start seeing things with a "gradient" including optical illusions, other UI elements on the screen, the items in your room that surround your monitor, the lighting in the room. If you can look at the photo of my monitor and claim to "see" a brightness gradient, then where is it in the bottom two images? If your gradient is the same as the one you are seeing in my photo, are you really sure it is even there?

 

[Leon Kowalski]

What I'm trying to do is understand what the threshold is for the
gradient issue vs. what's normal for an LCD screen. That's it.
This isn't about unrealistic expectations (at least not in my case).

A perfectly reasonable question. Apple repeatedly refused to give me
an answer when I asked for brightness uniformity specs on 24" iMacs.

The most widely accepted international standard for flat panel display
ergonomics is TCO'03. The certification agency is:

http://www.tcodevelopment.com/

You can find the detailed TCO'03 requirements document there, but in
a nutshell, the standard defines "luminance uniformity" as the ratio of
MAX:MIN brightness -- with the brightness measurements made at the
lightest and darkest regions of the screen (not necessarily the edges).

For TCO'03 certification, the ratio must be no greater than 1.5 : 1.

According to many published product reviews (tomshardware.com,
extremetech.com, tftcentral.co.uk, etc.) the 'typical' LCD monitor
easily meets the TCO'03 luminance uniformity requirements. Most
of the reviews I've seen report measurements of 1.2 : 1 or better,
even for bargain-basement, TN-panel economy models.

The tcodevelopment site also lists literally hundreds and hundreds of
TCO'03-certified monitors -- including virtually everything from Dell,
Acer, ViewSonic, Samsung and many others. Apple ACDs are on the
list -- but no iMacs.

Notice that some posts here pretend to "demonstrate" uniformity by
comparing the extreme right and left edges of the display. This is
pure silliness, since the "classic" brightness uniformity defect in 24"
ALU iMacs is an intense hotspot located at least several inches from
the left edge -- and sometimes, nearly at the center of the display.

For example, here's a photo of a display where the extreme left and
right edges seem to match almost perfectly, and it even looks good
when photographed with a big blue stripe covering the center of the
screen. But when you can see the whole thing at once...

https://forums.macrumors.com/posts/4373793/

...uh, you be the judge,

LK

 

[Digital Skunk]

lol denial

My 20" has a gradient (top-down gamma)
The 20" I saw in PC world has a gradient
The 24" I saw in PC world has the slightly different 24" gradient (left-right yellow/purple)

The 20" one is a characteristic of TN panels. Others I've used have the same issue.

The 24" one I don't know, but on the one I saw in PCW it was barely noticable and I'd never had noticed it if nobody had said about it here. It did exist though.


Regarding the sound, is this under Windows? Upgrading to the latest Realtek drivers alleviates the issue somewhat. It's still there but much less noticeable.

Saw this same thing on an HP monitor a few hours ago. It wasn't as bad when the screen saver was turned off though, but it was very noticeable when the screen had a solid color on it.

 

[Cloudane]

Saw this same thing on an HP monitor a few hours ago. It wasn't as bad when the screen saver was turned off though, but it was very noticeable when the screen had a solid color on it.

My old G4 12" Powerbook has it bigtime. Interesting fact - I'd never noticed it until people started mentioning it on the iMacs here!

It's noticeable on this very forum - the shading in the user details to the left of each post - at the top it's quite visible, at the bottom it almost blends in with the white background next to it.

It makes me feel a lot better to see it elsewhere. I wasn't really expecting such things from Apple, not when paying £950 for a desktop computer, but it's my own fault for not researching or considering that £950 is actually cheap for what it is (laptop hardware is much more expensive) and will therefore have "cheap" hardware in it.

If I could turn back time I'd get the 24", as it's *much* less noticeable.

 

[Digital Skunk]

My old G4 12" Powerbook has it bigtime. Interesting fact - I'd never noticed it until people started mentioning it on the iMacs here!

It's noticeable on this very forum - the shading in the user details to the left of each post - at the top it's quite visible, at the bottom it almost blends in with the white background next to it.

It makes me feel a lot better to see it elsewhere. I wasn't really expecting such things from Apple, not when paying £950 for a desktop computer, but it's my own fault for not researching or considering that £950 is actually cheap for what it is (laptop hardware is much more expensive) and will therefore have "cheap" hardware in it.

If I could turn back time I'd get the 24", as it's *much* less noticeable.

If I had the guts I find the 24" matte display and put that in the current model iMac.

 

[czachorski]

https://forums.macrumors.com/posts/4373793/

...uh, you be the judge,

LK

Ohh Geee. Are we going to have the entire discussion from the other thread (which is still actively going with good screens) all over again. Leon once again shows us all the challenges of photographing a screen of evidence of anything. The photo above was taken about 2 feet from the screen, which produces aliasing. Here is a great explanation of it:

It's called "aliasing" -- and has absolutely nothing to do with "refraction"
or "magical photons" acting differently for glass versus protein lenses.

You picked a distance where the pixel-spacing of the screen-image at
the camera's focal plane almost matches the pixel-spacing of the
camera's CCD (or a small integer multiple thereof).

Solution: Don't do that! Soften the focus and/or move the camera 2".

...we now return you to the "photography is a sham" thread,

LK

Here's another one with the same effect more pronounced (from my iMac, again):

Holy gosh: could it be......the same screen photographs differently, depending on how it is photographed?!?? No, couldn't be, now could it. Because that makes it real hard on those who want every iMac to be bad. Here is another one without the effect, which was achieved be following the directions of Leon with respect to brightness and distance:

Most iMacs in the wild will meet the specs Leon described. (The 1.2x ratio AND the 1.5 ratio). Some will not. If you are looking for something significantly better than 1.2x, you are going to be disappointed with the iMac, and probably most LCD screens. But at that threshold, you should ask yourself, will you be using the computer, or just testing it with a light meter?

And just to add, this is Leon's White iMac, which he claimed to have tested with a digital light meter, and I believe got a ratio of less than 1.2x. This shows you how much the color can change in a photo and still be within that spec. In real life (not the photo) it looks much better, I am sure.

 

[czachorski]

From: https://forums.macrumors.com/posts/4357738/

Here are some photos of my white 20" upgrade from the two ALU uglies. Uniform color, very good off-axis performance, and brightness uniformity approximately TEN TIMES BETTER than either of the ALU disasters.

http://picasaweb.google.com/TheLooby/White20IMacScreenPhotos

The screen's brightness is so uniform that my camera's light meter can't detect ANY variation at all. So, all I can say is that any "gradients" are below the meter's limit of resolution -- with LESS THAN 20% difference between max and min.

You be the judge. If this tests with a light meter within 20% (and claimed by Leon to show no variation):

Then what is this going to test?

 

[Fletchzky]

Today I went to the Apple store in Brea, CA to see if the 24" iMacs there had the gradiant issue. They had 6 machines there and out of the 4 I was able to check, all 4 did not have the gradiant issue. The other two were in use and the people weren't leaving anytime soon. However, one of the 4 did have the "welcome to the Apple store" image slightly burned into the screen. But they did not have any discoloration or fading issues of any kind on the screen when the background was changed to gray, medium gray or aqua blue.

Also, I stopped at Best Buy to check the 24" they have on display and it also didn't have any discoloration issues. Seeing this in person made me feel a bit more comfortable with getting one after Macworld.

 

[imacspert]

Got my new iMac today...

Ok guys,

So my new replacement iMac arrived today. And the screen looks the same as the one I replaced.

I am at loss here. Based on what I've seen in the last several posts, it appears that maybe what I'm seeing is normal? I don't know and am really confused. I don't feel like playing roulette.

Any advice is appreciated. I will try to put up a pic of the screen tonight.

 

[imacspert]

...and I just checked my local apple store

And talked to the store manager. She said she had never heard of the screen gradient issue and said that her 24" iMac (which she got the day it was released) did not have any screen issues. Halfway through my conversation with her, I pointed to a 24" with a grey background (and the left side was clearly brighter than the right) and she couldnt even tell there was any issue.

I also did the screen tests on some of the machines there and saw some difference b/t the left and right side...although not as pronounced as what I've seen before which I believe may have been due to the extra lighting in the stores (which tends to make it harder to tell the difference)

I am starting to believe that what I'm seeing is not 'the gradient issue'.

Czachorski: I am most convinced of this after seeing a pic of your grey screen. it looks like mine, and I think I may be making a big deal over nothing.

If we are correct, then I think there are ppl that are incorrectly stating online that if the left side of the screen is brighter than the right, then you DEFINITELY have the gradient issue.

Would love your opinions...

 

[frandavies]

one side of screen darker

hello all. i was looking for an answer to my imac glare problem (it nearly blinded me) and came across a thread telling of charcoaldesigns .com which supplies a free software to reduce glare, it works ok for me!

I just happened upon this thread about uneven monitor brightness and I realised I have the same problem. However, I bought from ebay a 24" stand alone monitor about two years ago and returned it to the seller as it had a problem with being blue in the bottom right hand corner. If you turn on shades from charcoaldesigns you can almost eliminate the problem.

It works for me and I just think there is a problem with screens over 20" but it does get better when the screen warms up

best wishes to all

Fran