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[david]

Greetings,

Today we have more choices than ever when shopping for an LCD (liquid crystal display). For a notebook, the quality of the built-in LCD can make or break a deal. Which LCD technology is best? The answer may surprise you because it varies depending on what you want to see---or don't want to see. In this discussion, we're going to focus on two of the major components of an LCD: The transparent LCD panel which contains the liquid crystals and the backlight that provides the illumination.
  
  
LCD Panels


TN (Twisted Nematic)
These may still be the most common type of LCD because they have relatively good production yields and are less expensive. Main points:

• lowest cost
• fastest response time (great for action games)
• lowest color accuracy (not good for photography if the panel size is large)
• highest color shift with viewing angle (most narrow viewing angles)
• medium blacks (medium contrast)

The quality of LCD panels can vary significantly from one manufacturer to the next. A high-quality TN can yield better color (when viewed straight on) than a low-quality IPS. So don't dismiss TN panels out of hand until you get more information. TN panels have been the top choice for many of the gaming monitors because of their speed---they can have the fastest response time. Their narrow viewing angle isn't usually a problem if the display is not too big. If you're considering the purchase of a notebook with a 13 to 15-inch screen, a TN panel will be small enough that the viewing angle will not vary too much. If you like to play first-person shooters (FPS) or games with lots of intense combat, you know how important the display response time can be---it can literally be a life saver (for your character).

VA (Vertical Alignment)
These panels have an interesting display technology that tries to combine the advantages of TN and IPS. Main points:

• medium cost
• good response time (not as fast as TN but still good enough for most action games, although some---not all---may have a little ghosting)
• good color reproduction (better than TN but not quite as good as IPS, some can achieve 99% sRGB and 75% aRGB, good for photography)
• medium color shift with viewing angle (between TN and IPS)
• darkest blacks (best contrast, best shadow detail, excellent for movies)

Remember, because quality can vary from one manufacturer to the next, a high-quality VA can yield better color than a low-quality IPS. In my opinion, VA panels are the universal choice. You really have to see a good one to appreciate them (I recently purchased a 40-inch Philips monitor with a 4K VA panel for use with my GT80 Titan and it is amazing). Why is VA the "universal choice"? Answer: A high-quality VA is fast enough for most action games, has excellent color and has the best black point. The blacks are inky black, providing excellent usable contrast that provides superior detail in shadows and dark scenes over all other affordable LCD panel types. If you like to watch lots of movies and/or like to play dark action games like Batman Arkham Knight or an outer space MMOG like EVE, you want good blacks. If you like to game with a big monitor, VA offers a wider viewing angle than TN and greater speed than IPS.

IPS (In-Plane Switching)
These have a reputation for the best color but the devil is in the details and this reputation is not always true.

• highest cost (but prices are dropping)
• slowest response time (not ideal for some gaming, but getting better)
• best color reproduction (some can achieve 100% sRGB and 99% aRGB, best for photography, 10-bit/channel and higher)
• lowest color shift with viewing angle (widest viewing angles)
• worst blacks (can't do full black, light leakage visible in dark rooms)

If most of the games you play are brightly lit with daylight scenes and lots of color, you may prefer a high-quality IPS panel. If you edit photos or movies and can tolerate the washed-out blacks when the ambient light is low (or you work in a well-lit environment), a high-quality IPS is hard to beat. If you need a wide-gamut display for prepress proofing, a high-quality calibrated IPS panel can yield almost 100% of the aRGB color space.

But buyer beware! There are some cheap IPS panels on the market now that don't live up to the full capability of the technology and are not a good choice. Plus, there is deception in the market with regard to the way LCD panels are spec'd and advertised. The most deceptive spec is the response time. Manufacturers are redefining the way they measure the response time so they can show lower (faster) numbers. But the IPS panels are not really as fast as they lead you to believe and you'll see ghosting in fast action games and high-speed sports events.

Unfortunately, the marketing folks have been very successful at convincing us all that IPS is the best. So even some of the gaming companies are bowing to market pressure and are adopting IPS panels for their top-of-the-line gaming monitors. This used to be the purview of fast TN panels---but not any more. The problem is, the IPS displays haven't yet achieved parity with TN display speed and their ability to produce good blacks is still lacking. They are getting better and the technology is improving---it may one day be the "universal choice"---but if you truly need a high-speed display and/or good shadow detail in a darkened room, IPS is not the choice to make.

What happens if your display is slow? Fast-movements will cause the object in motion to leave a sort of ghost trail behind it. This ghosting is just annoying---the real trouble comes when you need that ultra-fast twitch response to target and fire your weapon before your enemy ends your character's life!

Another spec that is often used to deceive buyers is the contrast ratio. This deception is common with IPS displays. With the right backlight, IPS panels are capable of being very bright. They use that brightness to claim an ultra-high contrast ratio. The problem is: IPS still has lots of light leakage at the dark end of the spectrum (poor blacks). That high contrast ratio spec is skewed way toward the bright end. It may work great if your IPS display will be used in a brightly lit environment (think of a room with lots of sunlit windows or outdoors). But, if you're hunkered down in a dimly lit room for a gaming marathon and your game has lots of dark scenes, the IPS display will have lower contrast in the dark portions of the scenes, causing the shadow detail to be compressed and lost. That super-high contrast spec meant nothing in real life (or virtual game life).

But there's another reason why those artificially high contrast ratios are deceptive---the monitors are too bright. You have to turn down the brightness for most "normal" uses. For example, I calibrate my monitors to a standard brightness of 120 cd/m^2 (note: a candela per square meter is equal to a lumen per square meter so cd/m^2 can be compared to popular lumen specs). Why 120 cd/m^2? Answer: This sets the brightest point within a good range for human vision to distinguish different shades at the bright end of the spectrum when the ambient room light is low to moderate. If the bright point of the display were set to 300 cd/m^2 for this same environment, the bright parts of an image would be so bright that your vision would lose some of its ability to "see" some of the bright detail. And, by turning down the brightness, you lose much of that inflated contrast spec that the manufacturer bragged about.

The place where brightness is important is when there is a lot of ambient light in the room. But if you're a gamer or a photo editor or a movie editor, you seldom want to operate in a brightly lit room. You often want to operate in a dimly lit room. If you need the extra lumens, by all means buy them. But don't be fooled into thinking that an insanely high contrast spec will translate into good shadow detail because, with an IPS display, it will not under the "normal" conditions for most gaming, photo editing and movie editing!

How much brightness is enough? For our purposes here (gaming), 300 lumens is plenty. It gives you more than enough headroom so you can calibrate the display (which usually involves turning down one or two of the RGB color channels more than others).

PLS (Plane-to-Line Switching)
This is Samsung's version of IPS and it has similar characteristics. Although I cannot be certain, it is my understanding that the 18.4-inch display in the GT80 Titan is a Samsung PLS. It looks very, very good. But it reports only 6 bits per RGB color channel to my NVidia driver. This probably means that it uses FRC (Frame Rate Control) to mimic 8 bits per channel.
  
  
Backlights


An LCD panel doesn't produce any light---it needs a backlight of some sort. The quality of the backlight can have a dramatic affect on the overall quality of an LCD. Some backlights cover the entire backside of the LCD panel. But most are located along the edges of the display and illuminate the entire panel from its perimeter.

WLED (White LED)
Uses blue LEDs with a yellow phosphor to achieve a neutral white backlight color that can provide a gamut a little wider than sRGB. This is the most affordable and common type of LED backlight. When you see a display advertised as an "LED" display, it usually means it is an LCD panel with a WLED backlight. This tells only half the story because a great WLED backlight isn't much good if its mated to a mediocre LCD panel and visa versa.

RGBLED (Red-Green-Blue LED)
Combines individual red, green and blue LEDs to achieve a neutral white backlight color that can produce a very wide gamut like aRGB and NTSC---and is very expensive (twice the price of WLED). RGBLED backlights are used for high-end displays that offer some of the widest color gamuts.

Older backlights
Incandescent -- cheap, bright but not uniform. You won't find these backlights any more for direct-view displays.

Cold Cathode Fluorescent Lamp or CCFL -- low power, bright, lasts longer than ELP, requires high voltage, dims greatly in cold conditions. Many of the cheaper LCD displays that don't use an LED backlight will use a CCFL backlight.

Electroluminescence Panel or ELP -- solid state, thin, uniform, low power but requires high voltage, shortest life---less than half the life of CCFL. If a cheap LCD display doesn't have an LED or CCFL backlight then it probably has an ELP backlight.

Generally speaking, the LED backlights (WLED and RGBLED) are the favored technologies because they can be very uniform, last the longest and are the most stable with age. But LED backlights are more expensive than CCFL and ELP so their adoption rate has been slow. Fortunately, prices have been dropping and WLED is now becoming affordable and common. The two most popular backlights prior to LED were CCFL and ELP. But they suffer from some serious problems. Both require high voltage power supplies which makes them more complicated to implement into a notebook and both lack stability, but for different reasons. CCFL is very sensitive to temperature. They are brightest when warm and can be quite dim under cold conditions. And they dim with age. ELP have relatively shorts lives because they dim the most with age. An ELP backlight that produced great brightness when new can be too dim in just a few years. This wreaks havoc for anyone requiring stable color calibration.
  
  
Color


A good IPS or PLS display will have the best color depth. Photographers love the models with 10-bits per RGB color channel (or better). This enables the monitor to display billions of different colors. To have good color a display should usually have at least 8-bits per RGB color channel which will enable it to display 16.7 million different colors. Both TN and VA display can easily provide 8-bits per channel.

Why are so many colors necessary? Answer: Our senses are not linear. Our hearing and our vision are exponential. That's why we can perceive such a wide range of sound and color. Yet our computer displays and televisions produce color on a linear scale. This doesn't mesh well with our exponential sense of sight because our vision can distinguish finer shades of color in the dark, dimly lit portion of an image than our displays can produce. The opposite is true at the bright end of the spectrum---our displays can often produce more bright shades than our vision can distinguish. In order to provide more shades in the dark region, our linear displays must be capable of producing huge numbers of colors.

There are a variety of color standards that can help us determine the range of colors (color gamut or color space) that a display can produce. I'll mention just two. The "sRGB" standard was invented by HP and Microsoft for computer monitors and HDTVs. It is also the default color standard for the internet. The "aRGB" (Adobe RGB) standard was invented by Adobe. It includes more colors (wider gamut) than sRGB and represents the colors that many professional printing presses can produce. For gaming, a display that can achieve 80% or more of sRGB would be good (90% sRGB would be very good). For editing photos for display on a monitor, projector or TV, a display that can achieve 90% or more of sRGB would be good (100% sRGB would be excellent). For editing photos for print media, a display that can achieve 100% sRGB and 75% or more of aRGB would be good (90% aRGB or more would be very good). These are rough guidelines---some professionals require higher standards.

To put this into perspective with human vision: The aRGB gamut (which is larger than sRGB) only covers about half of the colors that a human with good color vision can perceive. If you have good color vision, you can perceive far more colors than any computer display or TV can produce!

But IPS and PLS displays are not a panacea for color. Why? Because they usually have the worst blacks. You see, IPS and PLS displays struggle to block all of the light from the monitor's backlight. Remember, an LCD panel produces no light. It is a subtractive process. The backlight provides all of the light and the LCD panel layers subtract color from the backlight as the light passes through the panel. If an image needs a 100% red pixel, then the LCD panel's green and blue layers will attempt to block all green and blue light from the backlight so only the red light is able to pass through the panel.

The problem with IPS and PLS panels is that they cannot subtract as much light as good VA and TN panels can. Because IPS and PLS panels allow a little light to leak through, it prevents them from displaying a true black (no light). This isn't very noticeable if the monitor is used in an area with bright ambient light. But in a dark room, the problem will be painfully obvious---black areas of an image will look grey. This hurts the low-light color accuracy and counteracts an important part of an IPS or PLS display's vaunted color accuracy.

And that's not all---there is another quality that affects color accuracy. That quality is the viewing angle. Why? Because the viewing angle determines how well a display will continue to faithfully display color when viewed at an angle instead of straight on. This is unbelievably important to photographers because they rely on their displays to help them to accurately edit photographs. The problem is this: You can carefully calibrate the center of your monitor so the color accuracy is very good when you look straight on at the center of your monitor. But if you look at the same color at the side of your monitor, it won't look the same if the display's viewing angle is too narrow. What happens, is the color shifts as your eyes view the panel at an angle instead of straight on.

Imagine the difficulty trying to edit a photograph when only the color of the center is accurate. This problem is exacerbated if the monitor is very large because the viewing angles to the edges can be fairly large. This is another area where IPS and PLS shine compared to other LCD technologies. But VA displays are pretty good too---not as good as IPS and PLS---but good enough for many applications.
  
  
FRC


FRC (Frame Rate Control) is a clever technique to squeeze more colors out of a limited color depth. Using FRC, engineers can make an LCD panel with 6-bits/channel look like one with 8-bits/channel. Or it can make an 8-bits/channel panel look like one with 10-bits/channel. You get more bang for your buck! Sounds great, huh? It can be if it is designed very well and you are not one of the few people who have superman vision and can perceive the flicker.

You see, FRC does what it does by dithering the color of pixels with each new video frame, causing the eye to perceive a color that the LCD panel can't really produce. For example, suppose your monitor can produce red and blue but it can't produce purple. With FRC it will "dither" a purple pixel by switching it from red to blue with each video frame and you'll think you're seeing purple.

If FRC is implemented well, most people won't notice this dithering---all they'll see is great color. Having a monitor with a high refresh rate also helps. But if you have x-ray vision, the dithering will appear as a flickering of the image and it will drive you bananas.

But the saddest thing about FRC is that it makes it impossible to trust manufacturer color specs without knowing the true bits/channel. I almost purchased a great-looking 32-inch Quad-HD monitor from Hewlett Packard until I discovered that its 8-bit/channel spec was actually an FRC spec and its true color depth was only 6-bits/channel. It's still a great-looking monitor at an amazingly low price from a trusted name in the business. But I needed a true 8-bits/channel (or better) for my application which involved image editing and required higher-than-normal calibrated color accuracy. Shame on all manufacturers who conceal the true color depth. It underscores the old adage that if a deal looks too good to be true, it probably is.
  
  
Prices...


An interesting thing is happening in the computer display industry. Unfortunately, it doesn't affect notebooks but it will have a big effect on large-size external computer monitors. Both the computer and television industries are moving to the same resolution standard: 4K (3840 x 2160 pixels). The consumer TV market is vastly larger than the computer display market and will drive down the prices of 4K LCD panels. Up until now, most computer LCD panels were made primarily for the smaller computer market and were, therefore, more expensive. This is because the panels were too small for TVs (which is why the prices of notebook displays will not benefit from this convergence---they are too small for the TV industry and will not benefit from its vast economy of scale) or they had a resolution that didn't match any of the existing HDTV standards. But with the convergence of the desktop computer and TV industries on 4K panels, the computer industry will see LCD panel prices drop substantially because they'll be using the same panels made for TVs. We can expect to see VA, IPS, PLS come down in price much faster than we've ever seen with a new standard before.

My opinion is that this convergence will primarily benefit computer displays that are 40 inches or larger because this is the starting point for many HDTVs. And I think the sweet spot for computer 4K panel size is also 40 inches. It's small enough to sit on a desk but large enough to avoid scaling problems with Microsoft Windows (due to pixels that are too tiny). This is a panel size that will be made for many, many 4K TVs.
  
  
External monitor


Most of us who purchased a GT80 Titan did so as a desktop replacement. So it's no surprise that most of the time, mine is parked on my desk connected to one or more large external monitors. I've been itching to connect a 4K display to it and just made the jump with a monitor made with one of the new 4K panels described above. The trick was finding a monitor with one or more DP (Display Port) inputs because this is the only way to achieve a 60 Hz refresh rate at a 4K resolution from a Haswell or Broadwell Titan. (The Haswell and Broadwell Titan's HDMI port supports only version 1.4 which limits it to a 30 Hz refresh rate at 4K. HDMI 2.0 supports the faster refresh rate like DP but it wasn't available in a Titan until the Skylake version.) And finding a 4K TV with a DP input (which was my first choice) is still very rare.

After much reading and viewing, I purchased a Philips Brilliance BDM4065UC. It has a 40-inch VA LCD panel wedded to a WLED backlight. The LCD panel has a true 8-bits/channel color depth which is FRC-enhanced to 10-bits/channel. I'm driving it at 60 Hz from my GT80 Titan with two NVidia GTX 980M GPUs in SLI using the monitor's DP (Display Port) input. It replaced two 28-inch 1920 x 1200 pixel TN/CCFL monitors that are now happily sitting on my wife's desk expanding her Windows desktop. I calibrated the new monitor with an X-Rite i1Display Pro colorimeter. It's not a perfect monitor, but it's the best all-around display that I've found in its price range (US$800). Highly recommended! You can read a trustworthy and detailed review at the PC Monitors website here. Note: I receive no material gain from mentioning the above monitor and colorimeter. I spent many hours looking for a good and affordable 4K monitor and this is what I decided to purchase.

Kind regards, David

[glenns.email64]

Awesome write up David, thanks! (even if my brain does hurt a little now )

One question though. My Apache GE62 has Full HD, which seems to only describe resolution, and speaks little of panel type. My googling doesn't seem to produce much info either. Any idea what I'm actually staring at all these hours in front of my display?

In the store, it looked great next to a Dominator with an IPS, actually even more clear, but same resolution on a smaller screen will do that... I'm happy with it, I just don't know what breed it actually is.

Thanks for any insight!

[david]

Awesome write up David, thanks! (even if my brain does hurt a little now )

One question though. My Apache GE62 has Full HD, which seems to only describe resolution, and speaks little of panel type. My googling doesn't seem to produce much info either. Any idea what I'm actually staring at all these hours in front of my display?

In the store, it looked great next to a Dominator with an IPS, actually even more clear, but same resolution on a smaller screen will do that... I'm happy with it, I just don't know what breed it actually is.

Thanks for any insight!

Hi glenns.email64,

I'm glad you liked it but I apologize for the brain pain. :-) It took me a couple of weeks to organize my notes for the post because I had to squeeze it into my "spare time". And I wasn't sure whether MSI's forum could handle it all in one post---I thought I would have to divide into into several shorter posts. I'm glad I was able to upload it as a single post because it was quicker.

As for your Apache GE62, I regret that I cannot help. I had the same situation with my Titan. You won't find a spec anywhere that details the LCD panel in it. As I was doing research for the purchase, I discovered a review that said it had a PLS display. I had never heard of a "PLS" LCD panel and had to google it to discover that it is Samsung's version of IPS. But I haven't disassembled my Titan's LCD to see if this is true (and I don't plan to). Besides, it's not like I have much choice in the matter---hardly anyone is making an 18.4-inch panel so MSI was greatly constrained by what was available. On the other hand your Apache has a common notebook LCD size and will have lots of different panels that fit it. I've heard of modders swapping LCD panels in notebooks.

What's also surprising about this is the fact that MSI didn't brag about the Titan having a PLS panel. Stating that the Titan has a PLS display would have similar appeal to most shoppers as an IPS because of the brainwashing we've all been through. Usually, when a notebook or monitor manufacturer doesn't tell you what kind of panel or backlight are in their display, it means that it has a TN panel and a CCFL or ELP backlight.

Short of disassembling your Apache's LCD to discover the model number of your panel, the best advice I can offer is to search for reviews. Hopefully a reviewer somewhere listed what it is. I'm not an expert, but it is possible for experts to easily determine the type of LCD panel by inspecting it up close with a magnifier. You might be able to learn how to do this yourself.

Kind regards, David

[frank.tf.tsai]

Thank you for the very informative write-up!