How to check screen quality - 2017 27"

Discussion in 'iMac' started by Carlsbad Rich, Jul 28, 2017.

  1. Carlsbad Rich macrumors newbie

    Jun 11, 2016
    Awaiting new 27" Monday - have read about a few screens with shade differences (easily visible?) and backlight problems that were returned / replaced.

    What to look for / best way to ck. for backlighting issues?

    Just want to know what to look for and be pro-active if there are issues...

  2. SaSaSushi macrumors 68040


    Aug 8, 2007
    Takamatsu, Japan
    My advice would be to not actively seek out imperfections.

    If it looks good to you then it is good. Great is the power of suggestion and if there are easily visible defects, you won't have to look very hard for them anyway.
  3. Mac32 Suspended

    Nov 20, 2010
    If you really want to, you'll find some flaws no matter what. Unless the flaws are noticeable during everyday use, save your sanity and get on with life. Like backlight glow - there will always be a little of it in the screen corners, some "imperfections" can't be completely avoided.
  4. Lando555, Jul 29, 2017
    Last edited: Jul 29, 2017

    Lando555 macrumors newbie

    Jul 2, 2017
    I was following the discussions in this forum before ordering my new iMac especially because I was trying to decide which config to get. This forum is really a great help! For example, SaSaSushi here was a very helpful user in the discussion on which RAM to get for the new iMacs.
    OTOH, I take a very close look at new products I get anyway and some comments here won't help as some users seem to be even more precise and sensitive. So I decided to do what SaSaSushi suggests here. Just find a healthy way to look at your Mac and don't measure and analyze too much. This is for screen, heat, noise, whatever.
  5. iemcj macrumors 6502


    Oct 31, 2015
    This is a very important test and a good question to make sure the device you paid THOUSANDS of dollars for is actually doing what it says it's doing. Good thing is, it's easy to at least make sure you're getting the minimal performance.

    First thing, get your room totally dark. Wait till night if you have to, you're testing screen uniformity and it's crucial to have no glare or things to throw you off. Set your screen to 50% brightness as this is where baseline calibration is done.

    1, load up this image, it's full black. Makes sure it's even across the board, this is the easiest test since it's the bare bones requirement any screen calibrator will look at.

    2, load up this image, it's 80% grey. Slightly brighter than before but here is the crucial part, make sure it's 100% even across the board. No darker spots, not areas where it looks "dirty." Usually low end screens have a problem with this test but hopefully your 3,000 dollar imac doesn't

    3, load up this image, it's 20% grey so fairly bright. Same exact thing as before, make sure it's not getting darker by the corners and it's perfectly smooth across the full screen.

    4, load up this image, it's 100% white. An lcd screen should have zero problem making this look perfect but we're throwing it in anyway.

    If your screen is failing at even one of these and you're still under apple care/return window, do so immediately. There is absolutely no reason for that poor of quality control on something like this. Slight variances in color temp and tone are unnoticeable to anyone who isn't a full time photographer but for basic users, screen uniformity is absolutely a problem and it'll only get worse over time.
  6. Wrathwitch macrumors 65816

    Dec 4, 2009
    I agree, don't seek issues, if there IS a problem and you bought the warranty (even if you didn't) It should be good to return in a year.
  7. Carlsbad Rich thread starter macrumors newbie

    Jun 11, 2016

    Ding ding ding...

    Winner Winner....

    TYVM iemcj!

    Maybe I just wasn't clear enough for other responders, and while I appreciate their concern and advice, I wasn't asking for emotional counseling, but trying to learn and get the most out of this tool.

    I may not be a smart man, or a computer expert, or post very much on this forum, but I am certain I need the best screen possible because of eye surgeries and vision irregularities. I spend 6-10 hours a day using these tools for my business - huge part of my decision to purchase is the screen...

    Thanks again for answering my question "iemcj!"

    The internet is a funny place, but I'm starting to think it's here to stay, and that it serves many good purposes.

  8. iemcj macrumors 6502


    Oct 31, 2015
    Happy to help man. Don't worry in the slightest about color accuracy, these screens are extremely good out of the box and there's very little change unit to unit. I've had mine professionally calibrated and it's identical to the stock "imac" color setting so just leave it on that and never change it.

    The ONLY area of concern is screen uniformity. That's the value in these tests. The most crucial one is the all black test (again, be in a completely dark room) with the second most important being that "dark grey" test because if an LCD screen is going to have a problem, that's where it's going to show up.

    If your unit looks good, awesome! If not, at least you know one way or another and can take steps to get a replacement. Your screen is the single most important part of your imac so heck yeah make sure it's right. It would be completely unacceptable for someone to pay for the i7 processor and only get the power of an i5 so of COURSE make sure your screen that you will be using for literally every single task, make sure it works properly.
  9. SaSaSushi macrumors 68040


    Aug 8, 2007
    Takamatsu, Japan
    Trying to get the most out of it by asking for someone else to tell you how something is wrong with it that you can't detect by yourself? OK.
    --- Post Merged, Jul 30, 2017 ---
    Good advice. :)
  10. bbnck macrumors 6502a

    Mar 19, 2009
    I don't understand why people go to such great lengths like this. I agree with others - you have to draw a line somewhere. I go as far as a visual check around the iMac. If the computer starts up and performs normally while I install my apps and start using them, I presume everything else is fine and move on. Why is there a need to go any further than this? There is a warranty for a reason - it is designed to provide you with peace of mind that if there is something wrong, you don't need to go spotting for every flaw the day you receive the machine :confused:

    Just use it.
  11. Carlsbad Rich thread starter macrumors newbie

    Jun 11, 2016
    Again, Thanks iemcj!

    Just unboxed today and it is Amazing!


    17 557 8 gb (upgrading w/ crucial) 256 ssd (will go external / cloud for overflow no big files in workflow).

    When your not an expert, and a senior citizen on a budget, config etc. isn't simple- but a very helpful Senior Apple Tech recommended I7 for my work flow... and it is silent.

    Tools are important!
  12. SaSaSushi, Jul 30, 2017
    Last edited: Jul 30, 2017

    SaSaSushi macrumors 68040


    Aug 8, 2007
    Takamatsu, Japan
    Well, as iemcj points out, professionals like photographers are likely to be more sensitive to color variations, etc, but even on high end monitors from the likes of NEC and Eizo there is no such thing as a perfect display.

    On an iMac, if one (particularly someone who has to ask how to determine if it is bad or not) goes looking for color variances, some will decide they see them and thus begins an endless loop of returns and replacements.

    I've returned Macs for LCD panel replacements in the past under AppleCare. Twice, with two different machines were there was a dark smear that developed on the panels. This is a defect.

    iMacs with real color variance issues worthy of replacement will be obvious to anyone on a web browser with a white background.
  13. iemcj macrumors 6502


    Oct 31, 2015
    Exactly. Hence my suggestion to focus on screen uniformity using a solid white to black. Color can be calibrated and adjusted if need be, my 2015 imac was a little too magenta heavy in the midtones so I got it tweaked. This was the sorta thing that no normal user would notice let along worry about but as I have clients ordering 150k a year in wall prints, I need to be VERY sure what I see on my screen is how it's going to print from my photo lab. It's only because I'm a PITA that I would even notice or look for such a thing.

    But the screen uniformity, dark spots, or a heavy vignette on the edge of the screen can be distracting and quite noticeable even for average joe users. My old 2010 imac has a dark bottom left corner that has steadily gotten worse over the years, sure I can still surf the web and whatnot but it's why I suggest clamping down on this stuff early.

    And that's great for you personally but man, this is a 2-4 THOUSAND dollar investment and to most people, that's a big deal. If it was just a cheap 400 dollar Asus laptop? It would be judged that way. But for a machine that costs a month pay, a machine that brands itself on being high end, you can bet that we're going to make sure we are getting fully moneys worth.

    If I'm buying a used Toyota Corrolla for 800 bucks off craigslist, I'm not going to be too picky. Fairly low expecations. But if I'm buying a brand new 2017 Volkswagen Jetta diesel TDI for 60 grand, I'm going to be fully testing out and making sure I'm getting my moneys worth. Making sure the engine is running at peak performance, the wheels are in great condition, the air conditioning is optimal, and the paint is pristine. I'll be whipping it right back to the dealership if a mile down the road it starts making rattling sounds. That might be acceptable on a throw away car but NOT something high end and expensive.
  14. bbnck, Jul 31, 2017
    Last edited: Jul 31, 2017

    bbnck macrumors 6502a

    Mar 19, 2009
    I am not unfamiliar with display problems. I had to get my iMac replaced because it was suffering from image retention and was interfering with my development work.

    I do understand why people go to great lengths but I really do not like doing that myself. I'll no doubt just end up noticing something that I think is a problem that isn't. I do some checks and then draw a line and trust everything else is fine, knowing that if I spot something a few months later, I can contact Apple and get it fixed as I did with my last iMac.

    This is my way. If your way works for you, then continue doing it your way. It's all good.
  15. MacScott macrumors regular


    Jan 27, 2012
    Since I have gotten older, I don't see as well. Should I try to put together a few younger people to check my screen out to make sure it is working.
  16. iemcj macrumors 6502


    Oct 31, 2015
    I wouldn't suggest worrying about it TOO much. It would be worth having a second person take a look at it but honestly if you don't suspect there's a problem, it's likely not worth worrying about for you personally. It's one of those "if you have to ask..." sorta questions.

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