If you re read your own posts your focus remains on the buzzing issue in all of them. Returning a computer 3 times for a buzzing issue without verifying an acknowledged power compromise is.....insidious.
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The 2012 27" iMac is a fantastic system marred by poor quality control.
- Thread starter WilliamG
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If you re read your own posts your focus remains on the buzzing issue in all of them. Returning a computer 3 times for a buzzing issue without verifying an acknowledged power compromise is.....insidious.
I returned my iMac to the Apple Store because of image persistence.
What the Genius did was perform a 4-minute test and that's basically it. The test consists of displaying a checkerboard on the screen and looking away. If an iMac fails to reproduce said image persistence within that short time frame, there's apparently no problem as far as the Geniuses are concerned (which of course happened). I made several photos over the course of six months clearly demonstration the iMac suffers from heavy image persistence, but those were largely ignored. In the end I made them replace the LCD panel because of another minor anomaly.
What the Genius did was perform a 4-minute test and that's basically it. The test consists of displaying a checkerboard on the screen and looking away. If an iMac fails to reproduce said image persistence within that short time frame, there's apparently no problem as far as the Geniuses are concerned (which of course happened). I made several photos over the course of six months clearly demonstration the iMac suffers from heavy image persistence, but those were largely ignored. In the end I made them replace the LCD panel because of another minor anomaly.
That looks like it was shot in a dark room on a long shutter exposure? That being the case, it's quite difficult to assess how bad (or not) your screen is. All IPS panels are pretty crap at absolute black levels and if you photograph them in those conditions, they all look poor or dreadful.
How does it look in a normally lit room? i.e. normal viewing conditions?
Obviously the iPhone 5's camera increases the effect, goes without saying. No increased shutter time was used and the room was normally lit. Trust me, it almost looks just as bad in real life as it does on the photo. It's a huge difference compared to the previous panel. That one suffered from some bleeding as well, but nowhere near to the extent you're seeing here. The areas affected are much larger and it has a big yellow-ish spot right from the middle. The new panel also suffers from vertical lines that become visible on dark backgrounds regardless of it being day or night, something the old panel didn't have either. During the day it's somewhat less obvious, but does that mean I should just turn off the iMac when the sun goes down and suspend working on it?
I was pretty shocked when confronted with this. All in all it's incomprehensible how this panel could have made it to my iMac.
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Now people might jump on this, but that might well look "fine." I assume you have the brightness cranked to max? In that case, my iMac looks very similar. As has been pointed out, these panels are absolutely craptastical at uniform black levels, especially viewing angles to the corner. I'm a dim room, my brightness is at maybe 1/4 to 1/3. My blacks are still "glowly," but nowhere near as bad. There's no question your phone over-exposed that image, too, which didn't help.
If there are other issues with the display, well, - then you'd have more grounds to demand a replacement. From that above image, though, I'm not getting much.
Oh, and for what it's worth, when my iMac is set to max brightness on a black display, I can see very faint vertical lines, too, in the "glowy" areas. Not under normal usage, though. So if you can see them under normal usage, - exchange it. It sounds like you're not happy, especially by comparison to your last panel. I'd imagine what any of us say here won't matter, anyway.
Yep, the key is to keep a realistic brightness. Your iMac looks good.
Boy that's a tough one. I know I'd be nervous buying a 27" iMac somewhere that didn't have an easy exchange/return policy. QC might improve, but I'm not sure it will..
It may be one of your older posts, but I think it's more of a limitation imposed by the chosen design than a quality control one. If they deemed that truly unacceptable, they would have looked for other ways to improve or compensate for backlight bleed. I suspect enough people just run them at max brightness in bright rooms and don't notice enough to demand a replacement. There's a reason I don't like imacs.
Can't argue with that. And yes, I do think it's component/design choice to a large degree. That said, some panels are better than others, significantly, which is a real shame.
I think your last two sentences are intimately related.
Brands such as Eizo, NEC and Quato use similar LG panels, but they only use the best ones with decent uniformity and no dead pixels.
Apple seem to accept whatever quality LG send them, so it's more random - you might get a good one, you might not.
I am sure this is down to commercials. If Eizo are paying LG 2x what Apple are paying them (and I bet they are) then you can imagine how this happens. Volume probably plays a part too - Eizo and NEC probably take only a tiny number of panels compared to Apple sucking up huge volumes.
Same thing with the ipads. People turn them to 100% brightness, get in a dark closet and say how terrible their screen is.
I sympathize with.....
the OP, being burnt my fair share of times being an early adopter............. That said, I have read and heard a bunch of horror histories in the firsts batchs of iMacs. But quantity and quality of complaits appear to have lessened with time, IMHO....
the OP, being burnt my fair share of times being an early adopter.....
........ That said, I have read and heard a bunch of horror histories in the firsts batchs of iMacs. But quantity and quality of complaits appear to have lessened with time, IMHO....
Well I don't think the line would be solvent with a 50%+ return rate which is what you would have if everyone swapped multiple ones for the perfect unit. I mean the design realistically has to turn out in excess of 90% acceptable, probably higher than that, especially when that is just one component.
Those brands add a lot of their own engineering to it. I wouldn't say "whatever they're sending" either. You can't act like Apple has no part in the engineering. In the Eizo example, you'll find some of their lines share the same panel numbers, so there may be some internal binning. Also in their case on the CG line, you get a certificate displaying the averaged results per patch over 28 or so patches relative to their testing criteria. I can say having used so many different types, it's not only a matter of panels used. They make a big difference, but what the oems do with that panel is still significant.
That's not really everyone. A lot of work is done in subdued lighting so as to maintain minimal reflective interference and consistency. Of course you typically turn the display down too. I keep mine below 100 cd/m**2. Typically I would suggest people use it as they intend to use it and determine a problem that way. Examining it in the dark is merely a way to confirm results.
The bleeding issue is quite noticable at 40-50% brightness as well, so are the vertical lines. I cranked up the brightness to about 90% to make the issue more apparent when photographed. Don't get me wrong, I totally agree with you guys that some bleed is acceptable for this model (I accepted it of my previous panel), but I'm not getting anywhere near the results of Chippy99's iMac at 40%. Let alone 50%.Now people might jump on this, but that might well look "fine." I assume you have the brightness cranked to max? In that case, my iMac looks very similar. As has been pointed out, these panels are absolutely craptastical at uniform black levels, especially viewing angles to the corner. I'm a dim room, my brightness is at maybe 1/4 to 1/3. My blacks are still "glowly," but nowhere near as bad. There's no question your phone over-exposed that image, too, which didn't help.
If there are other issues with the display, well, - then you'd have more grounds to demand a replacement. From that above image, though, I'm not getting much.
Oh, and for what it's worth, when my iMac is set to max brightness on a black display, I can see very faint vertical lines, too, in the "glowy" areas. Not under normal usage, though. So if you can see them under normal usage, - exchange it. It sounds like you're not happy, especially by comparison to your last panel. I'd imagine what any of us say here won't matter, anyway.
As a whole I'm kinda disappointed with how much worse the new iMac's panel/backlighting is compared to my 2010 27-inch iMac. The viewing angles definitely took a turn for the worse, as well as black levels.
The bleeding issue is quite noticable at 40-50% brightness as well, so are the vertical lines. I cranked up the brightness to about 90% to make the issue more apparent when photographed. Don't get me wrong, I totally agree with you guys that some bleed is acceptable for this model (I accepted it of my previous panel), but I'm not getting anywhere near the results of Chippy99's iMac at 40%. Let alone 50%.
As a whole I'm kinda disappointed with how much worse the new iMac's panel/backlighting is compared to my 2010 27-inch iMac. The viewing angles definitely took a turn for the worse, as well as black levels.
I think the fused design contributes to this greatly. My 2009 27" iMac had less bleed/glow than my 2012, too. That said, I'd bet yours and Chippy99's iMacs are similar. Ambient light contributes to different results, for instance.
To be fair, my current Mac's screen is ***way*** better than the previous one that I had to RMA for other issues.
The issue can differ substantially on a per-panel basis. Ambient light levels really don't make up for it.
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Absolutely. I've had numerous iMacs for varying reasons. However, in a well-lit room it's usually VERY difficult to tell the difference between any of them. Most of the time I'd be willing to bet you wouldn't be able to tell the difference between a good iMac and a "faulty" iMac when you are in a well-lit room with windows during the day, with the iMac set to medium/high brightness.
The panel issues usually are most visible at night or in dimly-lit rooms. At that point, the problems can smack you in the face!
Suffice to say I'm not going to light up my house like Hiroshima just to compensate for Apple's lacking quality control.
But you're right, it's most apparent at night. Although this panel definitely showed its defect during the day as well.Suffice to say I'm not going to light up my house like Hiroshima just to compensate for Apple's lacking quality control.
Bit of an unnecessary analogy, but still, - you shouldn't have to have a ton of ambient light to mask the deficiencies in the panel, yes.
And to be fair, all IPS panels are pretty crap in terms of absolute black levels and uniformity and pretty unsuitable for night time viewing.
I have no idea why they have become so popular and the defacto standard for 27" screens. Samsung S-PVA is much better imho. It perhaps doesn't offer as potentially wide colour gamut (I say potential because without a wide gamut backlight, it's a moot point) but in terms of black level, contrast ratio and uniformity, S-PVA is a much better bet and far better suited as a "general purpose" panel to meet the requirements of the normal surfing/video editing/gaming/movie watching user.
I have no idea why they have become so popular and the defacto standard for 27" screens. Samsung S-PVA is much better imho. It perhaps doesn't offer as potentially wide colour gamut (I say potential because without a wide gamut backlight, it's a moot point) but in terms of black level, contrast ratio and uniformity, S-PVA is a much better bet and far better suited as a "general purpose" panel to meet the requirements of the normal surfing/video editing/gaming/movie watching user.
The repair guys at Apple agreed with my assessment: The quality of the LCD panel was unacceptable and shouldn't have made it into my hands. No discussion about it and he actually seemed a bit surprised about how bad the screen actually was.
I guess that's something.
I guess that's something.
Good result I suppose. Now, what was this thread titled again???
"The 2012 27" iMac is a fantastic system marred by poor quality control."
Seems apt, doesn't it.
(He says with his dodgy on/off button and stand that leans to the left!)
My power button is dodgy, too! When I press it it kind-of double clicks. It works, but isn't exactly inspiring...
Please explain, poor QC exists only in 2012 27 inch iMac displays? Only minor problems with 2012 iMac 21.5 inch displays? If so, I am wondering why.....