Response Times

A topic that usually comes up as a problem with LCDs is their slower response times relative to CRTs. While there's no doubt that even the best LCDs still exhibit some slight pixel smearing, the vast majority of users are okay with the level of performance we have available now. We also find it extremely difficult to tell the difference between various LCDs with response times ranging from as low as 3ms all the way up to 16ms. As with other specifications, there appears to be marketing influence on the final reported numbers.

To try to illustrate response times, we use our camera set to 1/80s shutter speed and a 2.5 F-stop at ISO-400. However, taking a picture of a display using a high shutter speed still isn't the same as looking at the display in person. LCDs run at a refresh rate of 60 Hz, and we use a shutter speed of 1/80s, so the net result is that we will capture an image of the display as it appears over a short period as opposed to an instantaneous look at the state of the various pixels. Image retention on your retinas also occurs, so even if you can eliminate the smearing effect at the display level you won't necessarily "see" a perfectly crisp transition. Then you have to consider some of the latest games are adding motion blur back in using DirectX 9/10 in order to make things look more realistic... but in that case, it's an artistic effect rather than a technological defect, right?

Links to previous response time images are below, taken during the Game 1 demo in 3DMark03.

Acer AL2216W #1 Acer AL2216W #2
Dell 2405FPW #1 Dell 2405FPW #2
Dell 2707WFP #1 Dell 2707WFP #2
Dell 3007WFP #1 Dell 3007WFP #2
Gateway FPD2485W
HP LP3065 #1 HP LP3065 #2
HP w2207

The advertised response time of the HP w2408 is "5ms on/off", or if you prefer 10ms TrTf (Time rising/Time falling). HP doesn't specifically list a gray to gray response time, but as the figure is more marketing than anything we might as well call it 5ms GTG. Judging by the pictures, we can as usual see portions of at least three frames. Accounting for shutter lag and pixel lag, the actual pixel response time is somewhere in the neighborhood of 16-25ms - the same as virtually every other LCD we have reviewed in the past 18 months. While that might sound like a lot, for the vast majority of people it won't present any problem. As always, if you're more likely to notice image lag, you might want to check out the display in person at a retailer store before making a purchase.

Viewing Angles Uncalibrated Results
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  • JarredWalton - Sunday, December 23, 2007 - link

    It's partly an issue of getting enough reviews done so that more manufacturers are willing to work with us on monitor reviews. Things take time, and sometimes we go through periods where nothing new comes out for a while. I've got at least a few more LCDs coming shortly, and I hope many more post-CES will get sent our way for review.
  • GlassHouse69 - Saturday, December 22, 2007 - link

    IPS panels are the best for all things. some s-pva or mva's are close competitors to ips but still have colour errors and colour washout on angles over 20 degrees from center.

    tn panels shouldnt be priced higher than 350 dollars. one could get an almost 0 lag (15-19ms) 24" s-pva panel from LG and be more pleased for gaming and general use for 500 dollars.

    i paid a grand for my 26" 1920x1200 H-IPS panel from planar. it is incredibly clear and accurate and has less than 1 frame lag. spending 550 dollars on a tn panel vs 900 dollars on a IPS pro fessional panel... sux cant see the point/value.
  • nevbie - Saturday, December 22, 2007 - link

    Have you lurked in the xtknight's LCD thread at the forums?

    Perhaps you might get ideas about what people seek from reviews and what kind of LCDs they seek.

    For me it seems that there are more interesting LCD models out there than reviews of LCDs. Pretty much the opposite situation when compared to GPUs or other less subjective review targets.

    Anandtech LCD reviews seem a bit bare for me, as there are less measurements than in some other LCD review sites. It is difficult to say if reviewers at the other sites measure things that I would notice though, or if the extra measurements just generate artificial desires. Input lag measurements at behardware or RTC error measurements at xbitlabs are interesting, for example, but I don't know if I would be bothered by less than ideal results in actual use.

    PS. The old comment system was better - no need to load/reload the article page when browsing comments.
  • 9nails - Saturday, December 22, 2007 - link

    What is "TN"?

    How about "S-PVA"?

    Bonus question: How do the two differ / which is better?
  • JarredWalton - Saturday, December 22, 2007 - link

    Well, I could try to explain it, but wikipedia already has a good deal of data on the matter. http://en.wikipedia.org/wiki/Thin_film_transistor_...">This Film Transistors

    The simple answer is that in my opinion:
    S-IPS > S-PVA > S-TN/TN+Film

    TN panels often have lower stated response times, but frankly I can't see the difference. I can however see the difference between the two in viewing angles and color quality.
  • trajan - Saturday, December 22, 2007 - link

    I know it should go without saying (and usually does) but thanks for another great review that is so clearly unbiased. Just seems to me that if Anandtech is having a hard time getting manufacturers to send LCDs for review, handing out a negative article on the first offering is probably not going to encourage other manufacturers to follow suite. But the truth is the truth, and particularly after recent high profile events on other sites its nice to get a little reminder of the quality we can enjoy here.

    (This probably is coming across all doe-eyed fanboyish.. meh. It's just really nice to have trust worthy info sources)
  • KorruptioN - Friday, December 21, 2007 - link

    The LG L246WP-BN is a P-MVA panel... it's beautiful and doesn't seem to exhibit some of the colour shifting that some PVA panels do. It'll be either that or Dell's next 24" for my next LCD.
  • gochichi - Monday, December 24, 2007 - link

    I recommend it at the $450.00 price tag. I own this display and I am very pleased with it overall. I vastly prefer the HDMI/DVI input as opposed to VGA on this particular display (some displays you literally can't tell the difference, not so on this panel).

    It is WORLDS better than the cheapish 24" Samsung. Samsung is building an overinflated name for itself... that or they are seriously risking their brand name over some "too good to be true" products (they really aren't good when you get them home).

    I more than ever depend on review sites and user comments to help me navigate the sea of available products. I personally believe that the Dell is superior to the LG 24", however, the LG is more readily available at retail stores and a fantastic deal at $449.00.

  • agull22 - Friday, December 21, 2007 - link

    I would like to see how HP plans to really markey this screen costing what it does and doing so litle for its return really. Right now though I am using my HP 42" Plasma as a monitor. I can honestly say it looks much nicer than the LCD equivalent. It would be nice to see something between the 42 and 26 size range though.
  • LoneWolf15 - Friday, December 21, 2007 - link

    $570? I paid around that price a year ago for a Dell 2407. I got an S-PVA panel, additional inputs (component, s-video), 9-in-1 card reader, 4 USB ports, and I got the five-year warranty.

    If HP thinks they can sell that panel for $570, they need to think again. 6-bit color, poorer viewing angle, limited inputs --you can do better for your money.

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