iMac 24" 3.06 background gradient

Discussion in 'iMac' started by Aaargh!, Nov 11, 2008.

  1. Aaargh! macrumors member

    Aaargh!

    Joined:
    Mar 21, 2007
    #1
    I've got a brand new iMac 24" 3.06 and it has the background gradient problem, it also has background bleed in one corner (left bottom). I've called the dealer and they claim they've never seen this and that I should come by to let them have a look at it.

    I've read about a lot of users complaining about this and I was wondering if it's worth the trouble to go back and send it in for repair or exchange, how are my chances of getting one that is gradient-free ? I'd rather not be without a computer for days or weeks while they look in to it or go through the trouble of exchanging and reinstalling all my stuff when the replacement will just have the same problem.
     
  2. joelw135 macrumors 6502

    joelw135

    Joined:
    Oct 15, 2008
    Location:
    New Jersey, USA
    #2
    I have a brand new iMac 24" and the only thing I see is a shading on the left and right, but that is from the back lights. Is that what you are referring to?
     
  3. Aaargh! thread starter macrumors member

    Aaargh!

    Joined:
    Mar 21, 2007
    #3
    Not just the borders, the left side of the screen is lighter than the right side, about the left 1/3rd is a few shades lighter, only really noticable on solid colors e.g. the medium gray background, or e.g. the 'quote' box above these lines, the greyish is a lot lighter on the left side. The gradient is over the whole screen from left to right, only the left 1/3rd has a steeper gradient.
     
  4. czachorski macrumors 6502a

    czachorski

    Joined:
    Sep 24, 2007
    #4
    You can measure it to be more certain of where you stand. There are several ways you can measure the gradient. One way it to take a picture with a digital camera (with the exposure turned down so as not to over saturate to the whites) and then use the digital color meter app (under utilities) to measure the color variation. Another is use a digital camera as a light meter by letting it auto-adjust the exposure as described here. The really bad ones that are drop-dead no doubt defective have a 200% or larger gradient. If you are in the 20-30% range, it is probably within specs for most LCDs and you might be sensitive to it. If it is the latter, you are probably going to be frustrated with the return process and may go through several units (one forum member claims to have gone through something like 20). If it is the former, you should definitely return it and get another one, and will most certainly be happy with the replacement.

    To put things in perspective, the images below are from my iMac, which I have measured several ways and found it to have a gradient of about 20-30%. Please note, that I can not notice this gradient during normal use - this thing looks perfect to me and everyone who has used it. But when I measure it, there is a slight gradient. You be the judge of whether yours is a fatal problem or not.............

    (click to enlarge)

    [​IMG]

    [​IMG]


    Extreme left and right edges cropped and put next to each other:

    [​IMG]
     
  5. Stelex macrumors newbie

    Joined:
    Aug 11, 2007
  6. RDoe macrumors member

    Joined:
    Mar 13, 2009
    #6
    Hmm I don't know if this is an option, how do you then calibrate the monitor?
    My problem, yesterday with unpacking it didn't really bother me, but now it becomes more clear. So change or just get a mini with 24ACD? I need some processing power for photo editing.

    See attachment, screenshot with camera of 20% left and right side of the screen.
     

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  7. mac.andy macrumors member

    Joined:
    Feb 22, 2009
    #7
    Ok I'm getting worried about these posts; I would assume such a high priced piece of equipment wouldn't have such panel problems. :(

    Apple must be using some real cheap panels to have these problems.

    Makes me wonder if I should stay with my iMac G4 until a new model is released with different panel technology (not TFT).
     
  8. czachorski macrumors 6502a

    czachorski

    Joined:
    Sep 24, 2007
    #8
    This post is from Nov 2008 and was resurrected by Rdoe. Prior to this post, there was a ton of these gradient issue posts right after the Alum iMac came out around Sept 2007. Such posts continued until early 2008, and then they thinned out big time. This one in November 2008 was one of the last ones I've seen here.

    Judging by the post frequency, I would guess that Apple had some significant design or manufacturing defect with the Alum iMac when it was first introduced in 2007, and that it took them a few months to correct it, and now what you are seeing is the normal, far less frequent issues associated with an occasional defective panel, rather than a systematic design defect.

    However - you should judge for yourself. Search the web and this forum for iMac screen defect issues, and go to the stores and look at them yourself. When the bad ones were real common, many here claimed to walk into Apple stores and see the gradients on every single machine in the store (although my experiences were just the opposite - I have personally never seen a bad one).
     
  9. RDoe macrumors member

    Joined:
    Mar 13, 2009
    #9
    That can be, but there are still problems! Do a search, even the early 2009 have problems. I'm not sure on getting a replacement or just cancel it and go for a LED ACD, but there are also some problems there.
     
  10. Mike in Kansas macrumors 6502a

    Mike in Kansas

    Joined:
    Sep 2, 2008
    Location:
    Metro Kansas City
    #10
    Your looks worse than normal. How does it look after being up and running for 1/2 hour to an hour or so? When you calibrate your monitor, you should wait at least half an hour to allow the monitor to come up to temperature. The gradient may become less noticeable after a while.
     
  11. itommyboy macrumors 6502a

    itommyboy

    Joined:
    Feb 26, 2009
    Location:
    Titletown USA
    #11
    Nice thread necro.

    Nonetheless what "czachorski" listed to try is pretty cool. I'm going to do it just for fun although none of my iMacs have ever had any display issues. Well none other than me not being able to remove myself from sitting in front of said display that is. :p

    For what it's worth Rdoe (I am by no means a display expert keep in mind) I'm with you in that the pic's of your display do not look good. From the looks of it something is wrong.
     
  12. RDoe macrumors member

    Joined:
    Mar 13, 2009
    #12
    full brightness warmup

    HI,

    when the display is set to full brightness and alter 10-15min when the display is warmed up then the gradient is less noticeable. But then the brightness is way to high! After using shades it is manageable. In my opinion this "work around" should not be normal... right?

    Pics now...
     

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  13. Mike in Kansas macrumors 6502a

    Mike in Kansas

    Joined:
    Sep 2, 2008
    Location:
    Metro Kansas City
    #13
    It should NOT be normal, but it is what many have resorted to even after having multiple 24" iMacs. Again, there is a huge internet buzz around the 24" iMac display gradient. I knew that going into my purchase, and have been fine. I can convince myself I see a gradient with an all white background and at lowest screen brightness. However, in actual use the gradient has not affected ANYthing I do, and even all of my photo prints come out just as I would expect them to.

    Also, when taking a picture of your screen, the gradient will look much worse in a picture than you would experience in actual use. You eye is able to compensate for small changes in brightness much faster than a camera or screenshot can; unless it is REALLY bad, it is a non-issue.

    However, like I had said a few posts up, the picture of your gradient looks more severe than what I am used to seeing.
     
  14. czachorski macrumors 6502a

    czachorski

    Joined:
    Sep 24, 2007
    #14
    Rdoe - you shouldn't have to tolerate turning your screen all the way up for it to look right. It is very possible that you got a defect. Try the camera as a light meter test I described in my post in this thread a few months ago. If your brightness gradient is in the 20-25% range, you might just be sensitive to these kind of things, and will probably find similar gradients in most large LCDs if you go looking. If it is 200-300%, you most certainly got a dud and should return it immediately. Anywhere in between, and you will have to be the judge of whether it is worth it to return it.

    My point earlier wasn't to say that there are no duds ever anymore - I am sure that a certain percentage of defective units is normal. But the deluge of bad ones that surrounded the initial launch has long since passed. It makes me think Apple had a big batch of bad ones in the beginning, or a design or mfg defect.
     
  15. darrellishere macrumors 6502

    Joined:
    Jul 13, 2007
    #15
    They all have the gradient issue, but after a while your eyes adjust to it & it doesn't seem like a problem anymore!

    Yours looks normal! for the 24". I had exactly the same anxiety and kept fixating on those faults, now i don't even see them, even doing critical photo work in aperture. I just always feel amazed by its beauty!

    They all have light bleed too, but in reality the only time you see it is when watching a dvd, before it starts and the screen goes all black.

    Just enjoy your beautiful imac and get some apple care off of ebay for peace of mind!

    PS Blu Ray look awesome on it, and you can take the polycarbonate glass off too (handy for cleaning or a change of look!)
     
  16. RDoe macrumors member

    Joined:
    Mar 13, 2009
    #16
    tests, what now, is "normal"

    So I did a test. I let the monitor warm up for 30min. Now the display in a daylight room at half brightness. I shot this photo using the settings as posted here above. The darker is the auto picture, the lighter one is close to how it looks right now.
    So change and hope for the best or "live" with it...
     

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  17. czachorski macrumors 6502a

    czachorski

    Joined:
    Sep 24, 2007
    #17
    Rdoe - nice job on the photos - it shows what you are describing well.

    What I did is use the application called "digitalcolor meter" under applications->utilities to hover around the photo and see how much the colors are shifting from light to dark. On both images, I am getting something like a 2x - 3x variation. On the dark one, the values go from the 20's to the 60's, and on the light one, they go from the 50's to the 90's.

    When I do they same thing on photos of my screen, I got something more like a 20-30% variation, whereas your is getting 100-200% variation. Give digitalcolor meter a try and see if you get the same results. If so, I would say that the level of gradient you are experiencing is abnormal, and I would exchange it for a new one.

    When most people are saying that the gradient is "no big deal" and they you will "get used to it", I would imagine that they are speaking about the more normal and expected gradients with LCD monitors in the 20-30% range, like mine, and not 100-200% like yours. To help see if this is going to be an issue for you, is this something that you notice only when it is on a solid background, or do you notice it even during normal use? If you can see it during normal use, you are definitely going to want another one. Here is how mine played out:

    Normal use - don't notice it
    Solid background - don't notice it
    Use of a light sensor on my screen - can tell by measurement there is a 20-30% gradient.

    To me, this seems a perfectly acceptable level of performance. Others will disagree and expect perfection, but I don't. Still others will have a noticeable gradient on a solid background, and not notice it under normal use and never even know it is there. Obviously, there is going to be a lot of subjectiveness out there on what is acceptable, and in the end, you will have to be the judge.

    Good luck! Please post back on how it goes.
     
  18. RDoe macrumors member

    Joined:
    Mar 13, 2009
    #18
    re-calibrate

    Hi, I did a quick recalibrate because my spyder doesn't do a good job on MAC and especially this one with the glass in front.
    Now it looks like this in full brightness, in daylight oke, but way to bright at darker surroundings.
    I guess this is as good as it gets? Even if I would trade it?

    Thanks.


    ps. I did notice something just yet! The screen is warmer on the left side. Could it be that there the CPU is? That would mean then, that the "extra" heat of the CPU causes the display to be warmer on one side. Ergo gradient? This would then be a design flaw which Apple will never fix, until a completely new iMac... in like two years? (just thinking out loud)
     

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