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Posted on September 18th, 2009 by David Bayon

Does anyone actually use dynamic contrast?

Samsung SyncMaster XL2370Playing around with Samsung’s XL2370 TFT this week, I hit a bit of a wall. In fact, not so much hit it, more slammed my head straight through it in sheer, irate frustration. You see, it uses an LED backlight, which Samsung’s press bunf confidently told me would produce a level of contrast the old CCFL kind simply can’t match.

And it does. Not just any old contrast, but MEGA contrast! Yes, MEGA, in capitals. In non-marketing speak that converts into a figure of 5,000,000:1, or 5,000 times higher than the standard contrast ratio on most of today’s TFTs.

Except the XL2370 doesn’t manage that at all. As with all of these ridiculous figures it’s a dynamic contrast ratio, and while it may be several magnitudes higher than the 10,000:1 or 20,000:1 of the best CCFL monitors, it still relies on adjusting the backlight on the fly during a video in order to maximise both the blacks and the whites depending on the type of scene.

Now, I’ve commented before in the magazine that I simply cannot bear dynamic contrast modes. I can count on one hand (with around three fingers to spare) the number of DCR modes I’ve ever seen that were even slightly bearable. I don’t even need fingers to count the number I’d actually contemplate using.

If you’ve never seen one of these modes in action, it goes something like this: during all but the most uniformly lit scenes the backlight swings wildly up and down to make shadows darker and highlights lighter in a manner that’s monumentally distracting and in no way better than what you had before.

The most brilliant DCR moment I’ve had was just a few days ago with the Samsung, as it looked at the blackness of a space scene in Wall-E, couldn’t tell there were stars scattered liberally across it and switched the backlight off entirely. It was certainly an impressive black level but it didn’t exactly help me follow the action.

Worst of all, I know the UK product managers at several TFT manufacturers hold the same opinion as I do on the subject. To them it’s nothing more than a figure the marketing department slap on the information card in the shop – and some have started doing so at the expense of any standard contrast ratio figure at all.

So who actually uses these terrible dynamic contrast modes? Do you have a monitor that offers DCR, and if so do you choose to enable it? Or perhaps you’ve been wondering why your films look so bad without realising your monitor came with DCR enabled by default?

I’m willing to admit I’m in the minority if it turns out you all love feeling nauseous during films, so if you’re a DCR fan do your best to convince me in the comments below.

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15 Responses to “ Does anyone actually use dynamic contrast? ”

  1. Paul B Says:
    September 18th, 2009 at 6:41 pm

    No, never use it, and totally agree with the article. Also never use it on TVs either because of the problems described.

    I’ve always thought the problem is that the monitor is trying to predict what the picture will do, and they’ll always be some latency involved in doing this?

    Anyway, you’d think they’d have got it working by now. Also don’t like manufacturer’s who quote the Dynamic contrast (DC) figure instead of the real, non-DC one.

     
  2. Paul G Says:
    September 18th, 2009 at 7:46 pm

    I’ve never used one but it sounds awful from how it’s described. Might this technology get a lot better with newer designs lighting each individual pixel? I believe, though might be wrong, that OLED works in that way. If some pixels boosted how white they got and others boosted how black they got we might have something more worth watching

     
  3. Stephen G Says:
    September 19th, 2009 at 12:46 pm

    I had a Samsung monitor where every time it powered down, changed resolution, or went into sleep mode it would re-enable the dynamic contrast and the artificial response time stuff. It did not last very long. Which was a shame because when these were disabled it was a decent enough screen? With them on however it suffered from the problems described above and from inverse ghosting. It also had noise around static windows from all this useless processing.

    From now on I’m going to stick to NEC, HP or some of the Dell panels. I can’t afford the Ezio ones, but I sure as hell will pay to avoid the horrors of using that Samsung.

     
  4. Phil Says:
    September 19th, 2009 at 3:32 pm

    Agree completely. The dynamic contrast setting was on by default on our LCD TV and made it horrendous to watch. You could see the back light going up and down depending on the scene. Really distracting (as much as those stupid logos we get now over most channels).

    Staying in a holiday home they had a 42″ LCD TV, can’t remember the make, and no where could you turn the dynamic contrast stuff off. The backlight was constantly going bright and dark.

     
  5. Steve Cassidy Says:
    September 21st, 2009 at 11:02 am

    A million thankyous to Dave and the respondents: you have just saved me a *massive* amount of money – I’m trolling about looking at telly snow and the predominance of the Samsung LED models was looking like a no-brainer.

    The Philips Ambilight doo-daah seems to be very similar to the logic used in Dynamic Contrast; is there any news from Ambilight owners on whether the Philips code is better than Samsung’s?

     
  6. David Bayon Says:
    September 21st, 2009 at 11:23 am

    @Paul G: don’t make the mistake of linking LED and OLED technology together – LED backlighting is barely a step up from CCFL, whereas OLED is on a totally different level of brilliance. It will also cost a fortune for a good while yet. You’re right though, when it arrives properly we can start talking about silly contrast ratios more seriously.

     
  7. Stuart Says:
    September 21st, 2009 at 11:41 am

    DCR is different from both ambilight and OLED. OLED pixels are their own lightsource, like plasma pixels (no single backlight). Ambilight adds to the ambiance of what’s being viewed by filling in some of your peripheral vision with a similar colour to that on-screen.

    I have to agree that DCR is distracting and always switch it off.

     
  8. computers Says:
    September 21st, 2009 at 5:53 pm

    Yes!I agree with you…DCR distracts and always it should be switch off…

     
  9. David Stapes Says:
    September 22nd, 2009 at 12:23 am

    Haven’t seen it in action but it sounds dreadful.

     
  10. Martin Stacey Says:
    September 23rd, 2009 at 10:05 am

    Automatically reverting to DCR mode looks like a *severe* usability problem. Like Stephen G @3, I’d regard that as a deal-breaker. You might like to check for this and include warnings in your reviews.

    (I’m worried if I need to check this, and how. I’m currently trying to pick an affordable good-for-everything TFT largely on the basis of your reviews. My shortlist is the Samsung T240, BenQ E2200HD, and Edge10 W243h. I *really* want 1200 rows (1440 would be far better) for big documents, but am struggling to justify 100 quid extra for size AND quality.)

     
  11. Steve Cassidy Says:
    September 23rd, 2009 at 11:23 am

    Martin, while I didn’t participate in the Labs, I did find a decent price/quality compromise (which means: I probably paid a bit over the odds to get quick delivery!) with an Iiyama Prolite E2607WS; not quite rock bottom, but also not stupid money – and importantly, it doesn’t do what my NEC’s do and keep on throwing up a whingeing pop-up about preferred resolutions!

     
  12. Robin How Says:
    September 27th, 2009 at 6:49 pm

    What’s needed is ambient light level correction with medium attack but v slow decay characteristics. That way when your lounge is lit by the sun, you can still see the orange faces of the day time TV hosts but in the evening you can enjoy the film within the dynamic range of the set. only the average level will be lower and you won’t get quantum steps in brightness relating to picture content.

     
  13. Den Pinplug Says:
    February 10th, 2011 at 10:20 pm

    The dynamic contrast should only dimm the backlight to the level of the brightest level in the digital signal over a whole frame, then increase the pixel “gain” level to match that of the original signal. Unfortunately this process requires a high backlight dimming response time and a very stable power supply, also requiring additional hardware to deal with the high ammount of data that needs to be processed! this would have to be delayed a frame to predict the backlamps brightness change! this costs money and more importantly development time. the better monitors only dim the lamps to a maximum of 50% these look better but only double the contrast ratio to something in the region of 1500:1 the native TFT display can only display 65000 (8 bit per colour) RGB “brightness” levels so higher than this contrast ratio is impossible without dynamic dimming! you also have the issue of ambient lighting levels resolve with transmissive displays! one day these features will be here, unfortunately Backlight and display electronics manufacturers are different companies both trying to make their product cheaper!

     
  14. meh Says:
    September 8th, 2011 at 2:00 am

    I use DCR while watching movies in complete darkness to have tolerable blacks (S-IPS panel). On any other _work_ it is annoying and useless.

     
  15. Shawn Says:
    November 1st, 2011 at 3:56 pm

    ok here’s the deal, i have a specific tv, an LG 55LK530. not sure if anyone knows anything about this tv, and not much actual information is obtainable on the internet. its a great tv. and i have been looking into calibration options. i have it set the best i possibly can based on all of the reasearch i have done. now the dynamic contrast setting. at first i turned it off and watched it for a while, because i have every other nonsense feature turned off as well. after a while tho i turned it on low setting, the picture popped. not too much in my opinion, but just right. i left it on. trust me i compared picture quality across several different sources to make sure i was not crushing blacks or gaining improper colors, with DCR on then off repeatedly. so i was wondering if anyone had any input on this particular set. also with the regular contrast setting, i have yet to find any reason not to crank it all the way up, as it seems i am not losing any quality or doing any bleeding together. the regular version of this tv is the LG 55LK520, mine is the same tv just the smart version. any input is appreciated.

     

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