20" iMac display strangeness

Discussion in 'iMac' started by djc6, Aug 11, 2007.

  1. djc6 macrumors 6502

    Joined:
    Aug 11, 2007
    Location:
    Cleveland, OH
    #1
    Hello,

    I picked up a 2.4Ghz 20" iMac today after much apprehension regarding the display. However, the glare is not my issue - in fact I can't see any glare writing this right now, and the display is leaps and bounds above the display on my 15" TiBook.

    Anyways, this is what I am noticing. Say I create a sticky and put it at the top of the screen - now I move it to the bottom of the screen. The color changes quite dramatically! Same thing if I have calculator open or anything else really and move it around from top to bottom of the screen. Is anyone else seeing this?
     
  2. Craiger macrumors 6502a

    Craiger

    Joined:
    Jul 11, 2007
  3. aliquis- macrumors 6502a

    Joined:
    May 20, 2007
    #3
    And if you get the 24" I'm very very sure you won't get a TN-panel so you will probably not have any such issues, you might not get an IPS-panel but atleast something better than TN.

    This is not only an issue with Apple thought, most people buy TN-panels, probably close to 100%, I can't understand why but I guess they only look at response time specifications and price. Idiots =P
     
  4. djc6 thread starter macrumors 6502

    Joined:
    Aug 11, 2007
    Location:
    Cleveland, OH
    #4
    So no one knows yet definitively what kind of display the 24" uses?

    I went back to the apple store today there was no *dramatic* change in color when I moved windows around or looked looked at an image that occupied the entire height of the screen.

    The apple store offered to let me exchange the 20" for a 24" and just pay the difference - no restocking fee.

    I tend to sit up/slouch/recline my chair and I find myself constantly adjusting the angle of the 20" display - because either the dock at the bottom suddenly gets washed out or the menu at the top becomes dark.
     
  5. BlackMax macrumors 6502a

    BlackMax

    Joined:
    Jan 14, 2007
    Location:
    North Carolina
    #5
    The viewing angle on the 20" iMac is 160°. This could contribute to the dock and top menu appearing washed out when you change your seating position. In comparison, the viewing angle on the 24" iMac is better at 178°.
     
  6. aliquis- macrumors 6502a

    Joined:
    May 20, 2007
    #6
    Not afaik, but I haven't done any extensive searches.

    http://en.wikipedia.org/wiki/TFT_LCD#PVA

    "MVA
    MVA (multi-domain vertical alignment) was originally developed in 1998 by Fujitsu as a compromise between TN and IPS. It achieved fast pixel response (at the time), wide viewing angles, and high contrast at the cost of brightness and color reproduction. Modern MVA panels can offer wide viewing angles (second only to S-IPS technology), good black depth, good color reproduction and depth, and fast response times thanks to the use of RTC technologies. There are several "next generation" technologies based on MVA, including AU Optronics' P-MVA and A-MVA, as well as Chi Mei Optoelectronics' S-MVA.
    Analysts predicted that MVA would corner the mainstream market, but instead, TN has risen to dominance. A contributing factor was the higher cost of MVA, along with its slower pixel response (which rises dramatically with small changes in brightness). Cheaper MVA panels can also use dithering/FRC.

    PVA
    PVA (patterned vertical alignment) and S-PVA (super patterned vertical alignment) are alternative versions of MVA technology offered by Samsung. Developed independently, it offers similar features to MVA, but boasts very high contrast ratios such as 3000:1. Value-oriented PVA panels also use dithering/FRC. S-PVA panels all use true 8-bit color electronics and do not use any color simulation methods. PVA and S-PVA can offer good black depth, wide viewing angles and S-PVA can offer additionally fast response times thanks to modern RTC technologies."

    Even if it's MVA/PVA it's probably a decent panel, just not as good as IPS.

    I think you test for it is weird, just look at the screen from the top and bottom and you will see how it gets washed out or dark depending on which way you look at it from, then watch it from the sides and it will probably turn yellow and the colors will get washed out.

    Also if you open an image with smooth gradients over different colors over the whole display you will probably see splitted fields of colors in it.

    But I don't know if the 24" is IPS, probably not since some review said it was worth than the old one, but I'm very sure it will be better than the 20" since 178 degrees viewing angles suggest it's not TN.

    Another alternative is that you get the Dell 2007 WFP, Philips 200W7PES or whatever it's called or Nec 20WGX2Pro or similair and hook that up aswell since those often are IPS-panels (they are cheap but the Dell and Philips are PVA if you are unlucky, sort of lottery, the Nec is always IPS but more expensive, still cheaper than an ACD, and much faster, and glossy.)
     
  7. macenforcer macrumors 65816

    macenforcer

    Joined:
    Jun 9, 2004
    Location:
    Colorado
    #7
    Just looked at the imac today. Horrible viewing angles. Display almost completely washes out at any angle. You must look directly at it. Not good.
     
  8. djc6 thread starter macrumors 6502

    Joined:
    Aug 11, 2007
    Location:
    Cleveland, OH
    #8
    Which? 20"? 24"? Both?

    I went back to the apple store and spent some time in front of a couple 24" models - I didn't notice any of the same business with the bottom of the display being lighter than the top. Tried standing, sitting, etc. and it seems much better than the 20". $300 better? Thats up for debate :)
     
  9. paetrick macrumors regular

    Joined:
    Jul 11, 2007
    #9
    Woaw that's really weird, the one i saw didn't have that problem at all !, Hope there isn't a 50 / 50 chance getting the good or bad 20" screen, Let's just hope yours was a bit defect !
     
  10. paetrick macrumors regular

    Joined:
    Jul 11, 2007
    #10
    Even on this 20 inch imac picture i can hardly imagine that it's a bad viewing angle from the bottom to the top:

    http://farm2.static.flickr.com/1314/1095626088_3031d0c7be_b.jpg
     
  11. CBAviator macrumors 6502

    Joined:
    Jun 10, 2007
    Location:
    Nederland
    #11
    What he is experiencing is not a matter of a good or bad screen. It simply has to do with the way the screen was created. It has a TN film which will make it act like a laptop screen in the way the color shifts. The 24" screens, however, don't have this TN film, rather, a higher quality component.
     
  12. paetrick macrumors regular

    Joined:
    Jul 11, 2007
    #12
    My existing asus 19" has a TN-panel, and there's NOT a color-change if i drag anything from the top to the bottom. neither had the imac i saw -> There can of course be defective ones.
     
  13. djc6 thread starter macrumors 6502

    Joined:
    Aug 11, 2007
    Location:
    Cleveland, OH
    #13
    I don't think it was just mine - I tried a couple 20s at the apple store... they all exhibited color changes from the top to the bottom of the screen. I tried a couple things... Moving Calculator.app from the top to the bottom of the screen - you'll notice the brushed metal looks good at the top and almost turns white at the bottom. Setup a green sticky at the top and an analogous one at the bottom - they're different colors.

    Put the dock on the left or right side of the desktop - the blue transparent background gets lighter as it goes down the screen. Pick a solid blue background - its lighter at the bottom as well.
     
  14. CBAviator macrumors 6502

    Joined:
    Jun 10, 2007
    Location:
    Nederland
    #14
    Huh. It must just depend on the screen then. I know my laptop certainly has color shift, however, it is much smaller so you don't notice the change nearly as much.
     
  15. djc6 thread starter macrumors 6502

    Joined:
    Aug 11, 2007
    Location:
    Cleveland, OH
    #15
    I picked up my 24" iMac today which I exchanged for the 2.4Ghz 20" iMac I originally purchased. This thing is unbelievably HUGE (my prior machine was a 15" TiBook).

    I'm glad I switched; the 24" display looks much nicer, is larger, and no such color changes as I move about! I'm also glad I can get the VESA mount kit should I ever want to put it on an arm for height adjustment. I'm not actually sure why the VESA kit is 24" only? I couldn't find any discernible difference between the back of either machine at the apple store.
     

Share This Page