New iMacs- 20" TN 6-bit panels?

Discussion in 'iMac' started by xtwentyseven, Apr 29, 2008.

  1. xtwentyseven macrumors member

    Apr 26, 2008
    Dallas, TX
    This has been asked in other threads, but not answered, so I figured it deserves its own thread. Does anyone know if they fixed the panel problem and upgraded the new iMacs 20" screen to 8-bit panels, actually capable of displaying the "millions of colors" that apple claims they can?
  2. Lord Zedd macrumors 6502a

    Lord Zedd

    Oct 24, 2007
    Denver, Colorado
  3. gnasher729 macrumors P6


    Nov 25, 2005
    There is no problem to be fixed. The 20" iMac is absolutely capable of displaying "millions of colors" by using a technique called "temporal dithering". The 24" iMac uses a different display that is also capable of displaying "millions of colors" and may have a better quality for its higher price. You get what you pay for, and you pay for what you get.

    Before you buy any monitor, whether standalone or as part of an iMac, you should go to a store where you can look at it in real life, and decide for yourself whether you are happy with the quality or not. If you are happy with it, buy it. If you are not happy with it, don't.
  4. trip1ex macrumors 68000

    Jan 10, 2008
    Yeah and folks forget we took a hit to true color when we switched from crts to lcds. Even the 24" iMac has to use a different technique to simulate some colors.
  5. macrumors regular

    Dec 6, 2003
    I keep reading about this TN 6 bit but I'm not really understanding.

    So the 24" has a much better screen than the 20" even with the new ones? There is more than just a size difference?
  6. inkswamp macrumors 68030


    Jan 26, 2003
    We did take a hit to true color in the switch from CRT to LCD but that was back in 2002. In the intervening years, LCD technology has made huge strides and had pretty much closed the gap. What was true back in 2002 is not an excuse for Apple to use cheap, low-quality displays on the iMac in 2008.
  7. daneoni macrumors G4


    Mar 24, 2006
    Has it really been confirmed that Apple are using TN panels in the new models?
  8. doug in albq Suspended

    doug in albq

    Oct 12, 2007
    for the 20's I am sure they are still 6bit or we would be talking about it on this forum. I bet dollars to doughnuts that the 20 aluminum imac will always be 6 bit, TN, and glossy.
  9. inkswamp macrumors 68030


    Jan 26, 2003
    Personally, I wouldn't consider any form of dithering to be a suitable replacement for the ability to actually display colors. Whether that counts as "millions of colors" or not, Apple should at least disclose this fact on their website, even as a footnote or in the tech specs for the machine. I find it deceptive on Apple's part and, judging by recent lawsuits, I'm not alone.

    And the idea that you can adequately judge a monitor's quality in a few moments of dicking around with a computer in a store is simply not realistic. Generally, you don't get a real feel for the quality of the display until after a significant amount of use at home. Part of the purchasing process involves using the monitor in the store and researching the product on the computer maker's site. If Apple doesn't disclose what they mean by "millions of colors" then how can a buyer make an informed decision?
  10. greg555 macrumors 6502a

    Mar 24, 2005
    I looked at the (original) glossy 20" and didn't like the viewing angle so I bought a white refurbished one.

    That said, I think "temporal dithering" is a valid way to achieve millions of colors. From what I understand that is how DLP projection TVs do it. The have millions of tiny mirrors that can be on or off (reflect light to the screen or away from it). To get more than 8 colors they turn each bit on and off rapidly to produce in-between levels of brightness.

    DLPs do have some artifacts (rainbow effect on single chip ones) but I don't think anyone claims they are not capable of producing more than 8 colors.

  11. inkswamp macrumors 68030


    Jan 26, 2003
    Yeah, there are arguments going both ways. I'm just on the "dithering does not equal true colors" side of it, but everyone has their own opinions. The fact that it's so subjective makes me believe Apple should be more up-front about the displays. At the very least, all sellers of displays using these techniques (including Apple) owe it to their customers to disclose the info on their site for the benefit of users who might prefer something else. To look at Apple's site, however, a buyer would have every reason to assume the displays in the 20" and 24" iMacs are pretty much the same. Even in the "complete specs" list, the displays appear to be pretty much the same. That is somewhat misleading.
  12. JayLenochiniMac macrumors G5

    Nov 7, 2007
    New Sanfrakota
    I wouldn't call a viewing angle of 160 degrees pretty much the same as 178 degrees, nor a brightness of 290 cd/m2 pretty much the same as 385 cd/m2.
  13. inkswamp macrumors 68030


    Jan 26, 2003
    That's pretty much buried in the iMac marketing hype pages and most people aren't going to know what to make of that in terms of how it applies to color or whether the displays are truly different or if those differences are somehow caused by the difference in size. There's no mention of that information on the specs list on the store pages, no link back to that information from the store, and to make things worse, Apple is using the term "millions of colors" when that's clearly debatable. All I'm saying is that a footnote on the "million of colors" blurb with a description of how that applies to the 20" model would be a little more honest.
  14. chlai macrumors newbie

    Apr 30, 2008
    have they fixed the wash out problem as well?
  15. ukmacmonster macrumors member

    Apr 29, 2008
    This is old news. All 20" Alu iMacs have cheapo TN 6 bit panels. People have been complaining about them from day 1, but they sell like hot cakes so an upgrade ain't going to happen. So either live with the cheaper display or buy a more expensive 24" iMac if a high quality display is important.
  16. ukmacmonster macrumors member

    Apr 29, 2008
    I'll take a modern high quality 24" LCD over an old CRT anyday.
  17. VoodooDaddy macrumors 65816

    May 14, 2003

    Dude, you have bitched enough about this issue, and frankly Im tired of reading it. If you dont like it DONT BUY IT. Its that simple.

    edit - ignore list FTW. Dude, I have NO problem with ppl voicing opinion and criticism. But seriously, I could easily dig up 20 posts of yours about the TN screens in the 20". Just got really old seeing it in thread after thread.
  18. D4F Guest


    Sep 18, 2007
    Planet Earth
    If it bothers you - don't read it.
  19. VoodooDaddy macrumors 65816

    May 14, 2003
    Typical excuse. I expected someone (him) to say that. You cant really tell when you click on a thread who has posted what. Try again. :rolleyes:
  20. jjahshik32 macrumors 603

    Sep 4, 2006
    Yes the 20" imac uses a TN lcd panel. The 24" imacs on the other hand uses a far superior H-IPS lcd.

    The current Apple Cinema Display line uses an S-IPS display and the H-IPS on the 24" imacs are actually a step up above the S-IPS panels.

    I believe the future Cinema Displays will incorporate the same H-IPS panels as the imacs + led backlighting.
  21. inkswamp macrumors 68030


    Jan 26, 2003
    Oh, boohoo. :rolleyes: The iMacs have been a disappointment, even with these "updates." I guess I stand out to you because I'm apparently one of the few Mac users in the world who will actually say something about it when Apple produces something of low quality instead of bowing down before Steve and licking his boots. Why does that bother you? Are you as annoyed with the people who repeatedly come to Apple's defense on every subject or do you filter that out?

    You could probably find more than 20. Big deal! The iMac's screen is a serious issue and I'm very annoyed by it as it's presently stopping me from buying a new Mac, something I've been wanting to do for several months. I'm damn irritated that these updates appear to have left the inexcusably low quality displays in place on the 20" models. For a company that likes to compare itself to BMW, that's just ridiculous.
  22. VoodooDaddy macrumors 65816

    May 14, 2003
    Then buy a 24". Is it that hard? How is this stopping you from buying one? Apple offers a low end model, the 20", which obviously used cheaper parts to keep the price down. And they offer a higher end model, the 24. I dont think Apple give a crap how you feel about the TN screens. They are doing just fine if you havent noticed.

    Do you complain about EVERYTHING like this? If so, God help the ppl that come in contact with you. Its fine to make your point a few times. But to continually harp on it gets really ***** old.
  23. KGB macrumors newbie

    Apr 24, 2008
    Agreed with D4F, it's typical because it's true. If you don't like it, pass over it VooDoo. It's often said for a reason.

    Your need to regulate or discourage what another member chooses to express is the only annoyance/turn off for most reading. The point of forums is discussion of opinion. Enjoy it. Contribute to it. Your inkswamp envy is showing.

    Re the 20" I'm in the same boat as many others, seeing as Monday's update didn't update the panel, or provide matte, I've ordered a refurbed white 20". Love that ALU design, but can't wait another 6 months, and ultimately I'm thinking the matte option may be done for the imac. It seems appple may want to have us buy an additional ADC for out matte needs.
  24. VoodooDaddy macrumors 65816

    May 14, 2003
    So Im reading the thread, I get to this post, how am I suppose to just "pass over it" without knowing what it said unless I read it? Its one thing if I see this person make a thread of their own that says "20" display sucks", obviously I can bypass that because Im pretty sure I know whats going to be said. But in this instance you are both wrong.

    And arent you both trying to regulate what Im saying in the thread? Hypocrisy at its best.
  25. CaptainChunk macrumors 68020


    Apr 16, 2008
    Phoenix, AZ
    Actually, the most offensive part of consumer DLP televisions is their use of "wobulation" (rapid pixel shifting) to create an illusion of full 1080p resolution. An HD2+ DMD chip is actually a 960x1080 array. The pixels shift horizontally to fake 1920x1080 resolution. 1,036,800 pixels for the "1080p" chip and 921,600 pixels for a 720p DMD chip (1280x720). As a result, it costs virtually no more to manufacture a 1080p DMD chip than it does a 720p one.

    Anyway....DLP works differently than temporal dithering on 6-bit TN LCD panels. The mirrors in the DMD chip tilt at different angles, controlling the amount of light that gets reflected, creating shades of the (typically) three primaries created by the color wheel. Contrast this with a CRT, which uses the same three primaries of red, green and blue that are shot at the screen's phosphor sheets at varying intensities to create a full color palette. Both are capable of reproducing the millions of colors claimed.

    Temporal dithering on 6-bit TN LCD panels is a cost-cutting measure that cheats to make colors. The panel itself is only physically capable of 262,144 colors; it creates this palette first with its primaries and then proceeds to fake all the colors in between by rapidly shifting between two similar colors that are actually in its palette to create a "new" color. It's easy to see how inferior 6-bit TN panels are to practically everything else by running test patterns. You'll see color banding on the TN panel, whereas you'll see a smooth transition on a good 8-bit LCD or CRT.

    In most real world consumer applications, ignorance is bliss. But a graphics artist, colorist or even some video editors can spot dithering from a mile a way.

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