Let's Talk Panel Technologies

We've already given a brief rundown of TN panels and what they offer, but let's expand that to include the other three panel technologies. Here's the breakdown:

LCD Panel Technology Comparison
Viewing Angles Excellent Excellent Excellent Okay Horizontal; Poor Vertical
Color Quality Usually Excellent Good to Very Good Usually Excellent Usually Good
Contrast Ratio >500:1 >500:1 >500:1 Usually >500:1
Color Gamut Depends on Backlight Depends on Backlight Depends on Backlight Depends on Backlight
Processing Lag 0ms (Usually?) 0-3ms 17-50ms 0-2ms
Response Time 6ms GTG 6ms GTG 6ms GTG Typically 2ms GTG
Cost Very High Very High? High to Very High Low to Medium

There are many similarities between IPS, MVA, and PVA - and note that these are now usually "Super" IPS/PVA or "Advanced" MVA. There are a few variants within the base panel type (i.e. E-IPS, H-IPS, and S-IPS), but the patterns generally remain true. Even TN panels have several areas that often overlap with the other techs. Let's look at the various areas in detail.

Starting with contrast ratios and color gamuts, modern LCDs have now reached the point where all panels will generally achieve a greater than 500:1 contrast ratio. Do not confuse this with "dynamic" contrast ratios, where the backlight can vary in intensity to help produce darker blacks and brighter whites at the cost of color accuracy - and it's also impossible to have bright whites and dark blacks concurrently, unless you have zoned backlighting, as current panels run the backlight at a uniform level for the entire display. Backlights also affect color gamut, with the key aspect being how much of the standard color spectrum the backlighting creates. Anything over 100% of Adobe RGB 1998 is overkill, and for most users even 82% of Adobe RGB 1998 (100% NTSC) is sufficient.

The other areas show more differentiation. Viewing angles greatly favor anything other than TN. It's worth noting that while vertical viewing angles often aren't as important as horizontal angles, if you want a display that can run in portrait mode you will definitely want to avoid TN panels (since in portrait mode the poor vertical viewing angles become horizontal angles). Manufacturers are also very generous in how they determine viewing angles, as they only require the display to maintain a 10:1 contrast ratio to qualify as "viewable". Realistically, we would say TN panels have a vertical viewing range of about 30° (15° up/down) before you notice severe image quality changes (i.e. from above the display becomes washed out, and from below it becomes very dark). Horizontal viewing angles on TN panels are probably closer to 60°, or even 90° if you're not super demanding. Compare that to the claimed 160° vertical/170° horizontal and you'll realize how inflated this spec has become with the target 10:1 contrast ration. In contrast, IPS/MVA/PVA all manage a fairly consistent 120° viewing angle in both vertical and horizontal alignments - possibly more if you don't mind the trapezoidal distortion caused by viewing from oblique angles. These displays advertise 176 or 178° viewing angles.

Color quality is also generally better on everything that's not TN, although here the (only) MVA panel we've tested seems to fall a bit short. When combined with viewing angles and the distortion that can cause to colors on TN panels, we'd stick with one of the other technologies if you want to get accurate color. In truth, this is mostly important for imaging professionals, as your eyes and brain will compensate to the point where you usually won't notice the difference. TN panels can also perform well in color accuracy, but they frequently do not because the manufacturers don't feel that's the target market - and in fact many displays have poor color accuracy by default because a lot of people prefer saturated colors. Also note that TN panels do not natively reproduce 8-bit color spectrums, relying instead on dithering and interpolation (switching rapidly between the two closest gray levels) to expand their 6-bit panels into pseudo-8-bit displays. This often shows up in color accuracy testing on TN displays with one or two colors having a high delta E while the rest are very close to ideal.

Pixel response times are another bloated statistic, with claimed response times of as low as 1ms for some TN panels and most now stating 2ms GTG (gray to gray). In theory, that would mean refresh rates of up to 500 Hz would be possible with no image persistence between frames. While no LCD currently available offers a refresh rate higher than 120Hz - and even those are relatively rare, only recently showing up with NVIDIA's 3D Vision technology - we still see image persistence on every LCD we've tested. That's not to say TN isn't a bit faster, but the difference is small enough that most users won't notice; either the response time will be "slow" on any LCD (relative to a CRT), or else it will be fast enough that you won't care.

Processing lag is potentially related to pixel response time. We don't know for sure if the lag comes after the crystal matrix receives a new voltage or if it comes before the voltage change, but we do know that of the tested panel technologies currently available, PVA seems to suffer the worst in this area by far. We only have one reference point on MVA panels, but we've read other reviews that support the idea that MVA response times are significantly better than on PVA. Processing lag can also come from hardware scalers used to support other resolutions, the prime example being Dell's 3008WFP. Even at native resolution, that display reportedly has anywhere from 10ms to 50ms of processing lag (depending on the revision that was tested). We have not seen any similar issues with other panels, most likely because scalers for lower resolutions have been around for quite a while and have been tweaked for optimal performance.

We also haven't tested any IPS panels outside of 30" LCDs, so we don't know for sure how IPS fares at other resolutions. Given 30" panels command a price premium, they may perform better overall than the smaller IPS displays; however, we believe IPS panels inherently process images as fast as any other LCD technology. Finally, it's worth noting that we have not been able to compare any LCD panel to a CRT for processing lag - we don't have access to any good CRTs anymore for comparison. Anecdotal evidence suggests that the best LCDs may still introduce a 15-30ms lag relative to a CRT. For better or worse, LCDs are here to stay and CRTs are a dying breed, so we'll constrain processing lag comparisons to LCDs and other newer panel technologies (i.e. OLED, SED, plasma, etc.)

Finally, we have to put all of this into perspective by introducing price into the equation. TN panel LCDs are by far the cheapest, often costing half as much as the same size display with an IPS/MVA/PVA panel. Since the non-TN displays do cater more towards professionals, some of the price difference may be artificial, but TN panels are still the least expensive option. They are also the oldest LCD technology, having been around since the dawn of LCDs. As much as you might want a high quality IPS display, when it comes down to a choice between a $400 22" IPS display or a $175 TN display, it's no surprise that a high percentage of people go with the inexpensive TN option.

So which panel technology is "best"? Clearly, it depends on many factors including pricing. Without price, I'd personally take an IPS display over any of the others, but again I may be biased by having only used 30" IPS panels. Many LCD HDTVs also use IPS panels, and given the recent growth in the HDTV market we'd expect there to be a few more improvements in the base technology. Like other displays, however, many HDTVs are now beginning to ship with TN panels, so if you're thinking about getting a new HDTV you'll definitely want to exercise care in what you buy.

Index A Closer Look at the BenQ FP241VW


View All Comments

  • JarredWalton - Wednesday, June 17, 2009 - link

    The glossy vs. matte debate is one of those areas that comes down to personal preference. Me, I really dislike glossies - and I know plenty of others that feel the same. However, I also know people that prefer glossy displays. More power to 'em, but I'm not going to encourage the trend. :-) Reply
  • photoguru - Wednesday, June 17, 2009 - link

    - Vizio 32" LCD Full HDTV (VO32LFHDTV10A) - $527 at Sam's Club US
    I've swapped out my 20" Apple Cinema Display for this 32" TV and I was completely shocked at the quality of the panel. If you run your image through one of the HDMI inputs text looks crisp and it even can run PIP for watching TV while working.

    I am a creative director and so I spend a lot of time staring at screens working on print, web, and television programs... I would like to have an LED back lit screen but for the money this thing is ridiculous.
  • iwodo - Wednesday, June 17, 2009 - link

    Are there any major different between panel type in terms of power consumption?

    And i really do hope either TN solve their "in-viewable" vertical viewing angle. ( Sorry "poor" in your article simply would not justify it ) with special coating that has been developed for a long time but there are yet wide spread of use.

    Or E-IPS will give the best performance per dollar. TN is possible the worst invention for Display Monitor history in All times.
  • aceh0 - Wednesday, June 17, 2009 - link

    The FP241VW launched in early 2007 and had nearly a two year run. Street pricing was under 500$ near the end of the product life cycle.
  • evilspoons - Wednesday, June 17, 2009 - link

    I found an missing-box demo model at a local computer store for $250, but I passed on it seeing the noticable lag between moving the mouse and seeing the cursor respond. That, and the asinine stand, made me keep looking. I hate my 22" Gateway monitor (it does a terrible job dithering) but I'm not going to spend money on virtually the same thing as a replacement, either (i.e. any other new monitor).

    I tried to buy an IPS 24" HP monitor a few months ago (lp2475w) but the distributor I attempted to order from jacked the price up $200 (from $700 Canadian to nearly $900 - ouch) in the time between me placing the order and it shipping, so I just cancelled.

    Then... I just gave up entirely because I realize I spend 99% of my computer time on my MacBook Pro now and I have to live with its LCD. Ha.
  • erple2 - Wednesday, June 17, 2009 - link

    Why not just buy directly from hp? They have it for 729 Canadian dollars. Was it really that much cheaper when you got it from the distributor than directly from hp? Reply
  • JarredWalton - Wednesday, June 17, 2009 - link

    Sorry for the error; I have clarified things now I hope. You're right that it first came out in 2007, but I believe it was announced early 2007 and actually available round about Sept/Oct. Anyway, it is discontinued, unfortunately just around the time the pricing was becoming desirable. You can find them online still at some places, but no major resellers carry them anymore so you'll have to take a bit of a chance if you buy one these days. Reply
  • IlllI - Wednesday, June 17, 2009 - link

    "The vast majority of LCDs these days are TN panels, and the trend appears to be moving even more in that direction. With a soft economy, many are looking for any way to save money, and even those who really like quality displays may be willing to settle for a less expensive TN panel"

    while TN is indeed cheapest, you can actually get a 22in e-ips lcd for around (or sometimes under) $200. while not as good as the more expensive ips panels, it is (in my opinion) better quality than TN. certainly, you guys know of it? http://forums.anandtech.com/messageview.aspx?catid...">http://forums.anandtech.com/messageview.aspx?catid...
  • Grooveriding - Wednesday, June 17, 2009 - link

    It's a real shame the tendency towards TN these days. Most consumers are just not informed as to the much more satisfying experience given by PVA/IPS panels.

    If you can get someone to sit in front of a TN and high quality monitor side by side that is usually enough to settle it, of course for some image quality is not a concern. For the enthusiast hardware user though, it usually is.

    I have an older LG246WP-BN which is a fantastic screen with great quality as well as a Dell 2408. Reading this article has made me think my eyes are bad though, as I prefer the IQ on my LG to the Dell, which according to this review ought to be superior with it's more modern panel tech.
  • The0ne - Thursday, June 18, 2009 - link

    Consumers are mostly going to want something average with a good low price. This isn't going to go away. And on most of their part they don't really care whether it's a TN panel or better because as long as it's "clear" and they like it then they'll buy it.

    I'll use myself as an example. I have 2 Dell 3007wfp-hc, 1 2407wfp, 2 22" viewsonics, 1 Acer 24" with TN, and 1 Acer 22" with TN. My main computer uses the 3007's of course but even when I switch to the other panels I rarely care. That's because the content I'm working with really doesn't require the extra 5-15% gamut, high contrast and so forth.

    Now if I really really care about colors, brightness, details and what have you then sure I'll spend the extra money on better panels and features. But then again why wouldn't I spend it on the medical LCDs :)

    I am pretty sure many of you commenting about wanting/needing a better than TN panel actually don't care whether you do or not on a daily basis. If you do you'll be a stickler like my co-worker who spends time paying attention to ghosting, blurs, etc EVERY time he uses his TV. I'm pretty sure many of you don't do this nor have the time to do this. If you do then....well, no comment. :)

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