Monitor technology
Panel Technology
CRTs have effectively been replaced by its thinner and brighter sister, the LCD. Under the umbrella of LCD technology, there are a few choices to consider before buying a monitor. First, you'll have to decide which panel technology is right for you.
The three main panel technologies currently used in LCDs are: Twisted Nematic (TN), Vertical Alignment (VA), and In-Plane Switching (IPS). Manufactures make the vast majority of consumer monitors using TN panels.
Not surprising, TN panels are the cheapest of the three technologies to make. With a few exceptions, monitors that cost $300 or less will likely have TN panels. The main advantages of TN panels are their fast--usually 2ms--response time and, of course, low price. Their major disadvantages are narrow viewing angles, relatively low brightness, and inaccurate color reproduction.
CRTs have effectively been replaced by its thinner and brighter sister, the LCD. Under the umbrella of LCD technology, there are a few choices to consider before buying a monitor. First, you'll have to decide which panel technology is right for you.
The three main panel technologies currently used in LCDs are: Twisted Nematic (TN), Vertical Alignment (VA), and In-Plane Switching (IPS). Manufactures make the vast majority of consumer monitors using TN panels.
Not surprising, TN panels are the cheapest of the three technologies to make. With a few exceptions, monitors that cost $300 or less will likely have TN panels. The main advantages of TN panels are their fast--usually 2ms--response time and, of course, low price. Their major disadvantages are narrow viewing angles, relatively low brightness, and inaccurate color reproduction.
Next up are VA (mostly seen as S-PVA) panels. VAs have improved viewing angles compared with TNs, better color reproduction, and they typically have a much higher maximum brightness. Also, they tend to have the lowest black levels of all three panel technologies. Unfortunately, a VA panel's response time and input lag are not quite as fast as a TN panel and they can cost anywhere from $400 to $800, and sometimes more depending on the panel's size. Also, you can expect a VA-based monitor's profile to be wider than a TN's.
Lastly, we have IPS. IPS-based monitors are usually the most expensive; however, the new e-IPS panels cost as little as $300 for a 22-inch model. They also have the best viewing angles of all three technologies and produce the most accurate colors; however, their blacks are not as deep VA panels. IPS monitors are the slowest of the bunch in both response time and input lag.
Backlight
Beyond panel tech falls backlight technology. Most monitors use cold cathode fluorescent lamp (CCFL)-based backlights--several fluorescent tubes stretched horizontally across the screen. Monitors that use Light Emitting Diode (LED)-backlights, however, rely on individual LEDs all over the back of the screen that turn off or on independently, giving the displays more precise control over the amount of light that comes through. The purported advantages of an LED backlight are better energy efficiency, more accurate color reproduction, a conceivably thinner panel design, and a higher potential brightness level.
Lastly, we have IPS. IPS-based monitors are usually the most expensive; however, the new e-IPS panels cost as little as $300 for a 22-inch model. They also have the best viewing angles of all three technologies and produce the most accurate colors; however, their blacks are not as deep VA panels. IPS monitors are the slowest of the bunch in both response time and input lag.
Backlight
Beyond panel tech falls backlight technology. Most monitors use cold cathode fluorescent lamp (CCFL)-based backlights--several fluorescent tubes stretched horizontally across the screen. Monitors that use Light Emitting Diode (LED)-backlights, however, rely on individual LEDs all over the back of the screen that turn off or on independently, giving the displays more precise control over the amount of light that comes through. The purported advantages of an LED backlight are better energy efficiency, more accurate color reproduction, a conceivably thinner panel design, and a higher potential brightness level.
However, so far only a few monitors have truly taken advantage of this technology. Also, so far, we've only seen LED-backlit monitors using TN panels, so don't expect great viewing angles or perfect color reproduction just yet on LED backlit monitors. Once we see some VA and IPS LED-based panels hit the market, we'll begin to see the true potential of the technology realized.
Which LCD panel is right for me?
Let's quickly sum things up.
TN
+ Lowest price
+ Fastest response time
- Inferior color reproduction
- Very narrow viewing angles
VA
+ Good viewing angles
+ Deep blacks
+ Medium price
- Color shifting on extreme angles
- Relatively slow response times
IPS
+ Good response times
+ Great color reproduction
- Expensive (e-IPS are more "medium price" however)
- Blacks not as deep as VA
Our best advice is to get what's right for you. Determine how you plan to use the monitor, and then decide which panel technology is best suited for you.
TN
+ Lowest price
+ Fastest response time
- Inferior color reproduction
- Very narrow viewing angles
VA
+ Good viewing angles
+ Deep blacks
+ Medium price
- Color shifting on extreme angles
- Relatively slow response times
IPS
+ Good response times
+ Great color reproduction
- Expensive (e-IPS are more "medium price" however)
- Blacks not as deep as VA
Our best advice is to get what's right for you. Determine how you plan to use the monitor, and then decide which panel technology is best suited for you.
LCD Monitor basics
Aspect ratio: Although some people contend 4:3 monitors are still best for surfing the Web, the vast majority of monitors available for purchase today have a width to height proportion (or aspect ratio) of 16:10, with 16:9 coming in at a very close second. For the last few years, with the advent of wide-screen monitors, most screens have been of the 16:10 variety. Starting in late 2008--and picking up steam in 2009--monitor vendors have really been pushing out 16:9 monitors as fast as they can make them.
This shift to 16:9--and by association to a 1080p (1,920x1,080 pixel) resolution--aspect ratios stems from the industry's desire for monitors to become more like HDTVs, and this seems to be the direction the computer monitor industry is headed right now. Companies will most likely still release professional-grade monitors where precise colors are crucial, in the 16:10 aspect ratio, as there really is no good reason to change ratios.
Still, today it comes down to 16:10 or 16:9 ratios. The difference between the two ratios is most prevalent while watching movies. On a 16:10 monitor, you have a choice when watching a movie filmed in 1.85:1 aspect ratio, such as on "Sin City." You can either watch it letterboxed format at its original 16:9 aspect ratio, or watch it in full screen with the image stretched to fit the screen. On a 16:9 monitor you can watch the same movie in full screen with no stretching. Movies shot in 2.35:1 (like "Iron Man") are always letterboxed, whether on 16:9 or 16:10 monitors unless you zoom the image.
Essentially, a 16:9 monitor can display a full-screen 16:9 Blu-ray or digital movie shot in 1.85:1 without stretching the image to fit the screen. A 16:10 monitor will need to stretch the same movie's image a bit to get it to full screen without any black bars.
Black Level: No display can show black without some light seeping through. Black level is a measurement of how much light emanates from the display while showing black.
Brightness: A measurement of how much light a panel can produce. Luminance is expressed in candelas per square meter (cd/m2). A measurement of 200 to 250 cd/m2) is OK for most productivity tasks; 300 to 400 cd/m2 is great for movies and games.
Contrast ratio: The difference in light intensity between the brightest white and the deepest black. While contrast ratios typically don't exceed 1,000:1 on monitors; lately, manufactures have been pushing Dynamic Contrast as a spec, and sometimes misleadingly calling it contrast ratio.
Before a monitor is released to the public, panels go through testing in the vendor's own lab. These tests produce the specs that the vendor will then publish with the release of the monitor. Specs such as maximum brightness, pixel pitch, pixel response time, contrast ratio, and dynamic contrast ratio are all determined in the vendor's lab.
When testing normal contrast ratio, vendors use a device that measures luminance to determine how much light is emanating from a display while it's showing both a completely black and a completely white screen. They then take each number, do a bit of math, and come up with the contrast ratio.
Now, aside from a relatively low number of LCDs that use LED-backlighting technology, all LCDs have a lamp built in to their screens. When you turn your brightness setting down, you're actually just dimming the lamp in the back. When the vendors dim the backlight to get the contrast ratio score, they dim it to a point, but do not turn it off.
When they test to get the readings for Dynamic Contrast, however, they turn off the backlight. With the backlight off, the darkness of the black level increases by a factor of 10 or more. At this point, the vendor takes its reading for the dark screen and compares it with the white screen reading it recorded earlier. Since this new dark screen level is so dark, it increases the contrast ratio. The problem is that the screen only gets this dark when the video signal is black or near black--not very useful when you're watching a movie, or playing a game, or doing pretty much anything. The primary reason for including this feature is that the contrast ratio goes from 1,000:1 to 10,000:1, and even 30,000:1. When vendors push Dynamic Contrast as a spec for LCDs that use LED-backlighting technology, however, it may be more appropriate. Direct contrast ratio works differently with LEDs than with lamp-based LCDs. When a portion of an image in a movie is relatively dark, the LEDs in that local area of the screen are dimmed. This occurs on a frame-by-frame basis and lowers the black level in that dark area only. Unfortunately, this implementation has its weaknesses, as well, as there can be some noticeable visual glitches in the areas that darken.
Bottom line? Take all measured specs with a grain of salt; however, take Dynamic Contrast specs with a huge bucket load of salt.
DisplayPort: Heralded as the successor to DVI and HDMI, DisplayPort is a higher bandwidth connection that could facilitate thinner and lighter monitors as they would no longer require special circuitry (and hardware to run that circuitry) to receive video signal. Adoption of this technology has been sparse, so far to say the least.
DVI: Some newer monitors forgo including Digital Visual Interface (DVI) in favor of HDMI. If this is the case with the monitor you're interested in, make sure the monitor includes a DVI to HDMI cable or that your video card supports an HDMI connection. Having said that, we recommend getting a monitor with at least one DVI connection.
HDMI: An HDMI connection is used to connect the display to a high definition source, such as a Blu-ray player, video game system, or a DVR-based HD cable/satellite set-top box. HDMI connections have become more common recently and it's the exception now when a monitor, 22 inches and larger, doesn't have one. If you're planning to use your monitor as a television, this is an essential feature.
Pixel-response rate: This refers to how quickly a pixel can change colors, measured in milliseconds (ms); the lower the milliseconds, the faster the pixels can change thus reducing the ghosting or streaking effect you might see in a moving or changing image. Based on new evidence, however, it's likely you won't see any streaking or ghosting in a modern LCD when watching a movie.
Input lag: A delay in which the LCD's image lags behind what's been sent to the screen. Not everyone notices input lag and vendors rarely, if ever, quote this figure for their monitors. Input lag affects gamers the most. If split-second reactions are paramount in your gaming sessions, do some research as to a monitor's input lag before you buy.
Ergonomic options: Most LCDs offer some degree of screen tilt, usually 30 degrees back and 5 degrees forward. Some include a swivel feature, many offer height adjustability, and some panels can also pivot between portrait and landscape modes, making legal-size documents and Web pages easier to view. Some LCDs can be attached to VESA-compatible mounts that connect to third-party wall mounts or swinging arms. Resolution: Dictated by screen size, aspect ratio, and sometimes the manufacture's digression. Make sure you are comfortable with an LCD's native resolution before you buy it. Remember, an LCD that scales its image to a non-native resolution will never look as good.
This shift to 16:9--and by association to a 1080p (1,920x1,080 pixel) resolution--aspect ratios stems from the industry's desire for monitors to become more like HDTVs, and this seems to be the direction the computer monitor industry is headed right now. Companies will most likely still release professional-grade monitors where precise colors are crucial, in the 16:10 aspect ratio, as there really is no good reason to change ratios.
Still, today it comes down to 16:10 or 16:9 ratios. The difference between the two ratios is most prevalent while watching movies. On a 16:10 monitor, you have a choice when watching a movie filmed in 1.85:1 aspect ratio, such as on "Sin City." You can either watch it letterboxed format at its original 16:9 aspect ratio, or watch it in full screen with the image stretched to fit the screen. On a 16:9 monitor you can watch the same movie in full screen with no stretching. Movies shot in 2.35:1 (like "Iron Man") are always letterboxed, whether on 16:9 or 16:10 monitors unless you zoom the image.
Essentially, a 16:9 monitor can display a full-screen 16:9 Blu-ray or digital movie shot in 1.85:1 without stretching the image to fit the screen. A 16:10 monitor will need to stretch the same movie's image a bit to get it to full screen without any black bars.
Black Level: No display can show black without some light seeping through. Black level is a measurement of how much light emanates from the display while showing black.
Brightness: A measurement of how much light a panel can produce. Luminance is expressed in candelas per square meter (cd/m2). A measurement of 200 to 250 cd/m2) is OK for most productivity tasks; 300 to 400 cd/m2 is great for movies and games.
Contrast ratio: The difference in light intensity between the brightest white and the deepest black. While contrast ratios typically don't exceed 1,000:1 on monitors; lately, manufactures have been pushing Dynamic Contrast as a spec, and sometimes misleadingly calling it contrast ratio.
Before a monitor is released to the public, panels go through testing in the vendor's own lab. These tests produce the specs that the vendor will then publish with the release of the monitor. Specs such as maximum brightness, pixel pitch, pixel response time, contrast ratio, and dynamic contrast ratio are all determined in the vendor's lab.
When testing normal contrast ratio, vendors use a device that measures luminance to determine how much light is emanating from a display while it's showing both a completely black and a completely white screen. They then take each number, do a bit of math, and come up with the contrast ratio.
Now, aside from a relatively low number of LCDs that use LED-backlighting technology, all LCDs have a lamp built in to their screens. When you turn your brightness setting down, you're actually just dimming the lamp in the back. When the vendors dim the backlight to get the contrast ratio score, they dim it to a point, but do not turn it off.
When they test to get the readings for Dynamic Contrast, however, they turn off the backlight. With the backlight off, the darkness of the black level increases by a factor of 10 or more. At this point, the vendor takes its reading for the dark screen and compares it with the white screen reading it recorded earlier. Since this new dark screen level is so dark, it increases the contrast ratio. The problem is that the screen only gets this dark when the video signal is black or near black--not very useful when you're watching a movie, or playing a game, or doing pretty much anything. The primary reason for including this feature is that the contrast ratio goes from 1,000:1 to 10,000:1, and even 30,000:1. When vendors push Dynamic Contrast as a spec for LCDs that use LED-backlighting technology, however, it may be more appropriate. Direct contrast ratio works differently with LEDs than with lamp-based LCDs. When a portion of an image in a movie is relatively dark, the LEDs in that local area of the screen are dimmed. This occurs on a frame-by-frame basis and lowers the black level in that dark area only. Unfortunately, this implementation has its weaknesses, as well, as there can be some noticeable visual glitches in the areas that darken.
Bottom line? Take all measured specs with a grain of salt; however, take Dynamic Contrast specs with a huge bucket load of salt.
DisplayPort: Heralded as the successor to DVI and HDMI, DisplayPort is a higher bandwidth connection that could facilitate thinner and lighter monitors as they would no longer require special circuitry (and hardware to run that circuitry) to receive video signal. Adoption of this technology has been sparse, so far to say the least.
DVI: Some newer monitors forgo including Digital Visual Interface (DVI) in favor of HDMI. If this is the case with the monitor you're interested in, make sure the monitor includes a DVI to HDMI cable or that your video card supports an HDMI connection. Having said that, we recommend getting a monitor with at least one DVI connection.
HDMI: An HDMI connection is used to connect the display to a high definition source, such as a Blu-ray player, video game system, or a DVR-based HD cable/satellite set-top box. HDMI connections have become more common recently and it's the exception now when a monitor, 22 inches and larger, doesn't have one. If you're planning to use your monitor as a television, this is an essential feature.
Pixel-response rate: This refers to how quickly a pixel can change colors, measured in milliseconds (ms); the lower the milliseconds, the faster the pixels can change thus reducing the ghosting or streaking effect you might see in a moving or changing image. Based on new evidence, however, it's likely you won't see any streaking or ghosting in a modern LCD when watching a movie.
Input lag: A delay in which the LCD's image lags behind what's been sent to the screen. Not everyone notices input lag and vendors rarely, if ever, quote this figure for their monitors. Input lag affects gamers the most. If split-second reactions are paramount in your gaming sessions, do some research as to a monitor's input lag before you buy.
Ergonomic options: Most LCDs offer some degree of screen tilt, usually 30 degrees back and 5 degrees forward. Some include a swivel feature, many offer height adjustability, and some panels can also pivot between portrait and landscape modes, making legal-size documents and Web pages easier to view. Some LCDs can be attached to VESA-compatible mounts that connect to third-party wall mounts or swinging arms. Resolution: Dictated by screen size, aspect ratio, and sometimes the manufacture's digression. Make sure you are comfortable with an LCD's native resolution before you buy it. Remember, an LCD that scales its image to a non-native resolution will never look as good.
Memory card readers: A few monitors have media card readers built into the bezels. This is a handy addition for digital photo enthusiasts who want to see their pictures without using a PC.
USB: Many displays have USB ports. Typically, they are not powered hubs, but simply convenient ports to connect low-powered devices such as a keyboard or a mouse, thereby reducing the tangle of cables that run back to the computer.
Audio: Some monitors offer audio functions, either as standard items or as optional accessories. These may include a headset jack, a volume control, or embedded speakers. In general, these speakers are of limited quality, and an inexpensive $30 speaker set from an office-supply or computer store will often provide much better sound.
Viewing angle: Largely dictated by panel technology. The physical structure of LCD pixels can cause the brightness and even the color of images to shift if you view them from an angle rather than facing the screen directly. Take manufacturer's specifications with a grain of salt and make your own observations if possible.
HDTV: As work and entertainment products continue to converge, many monitors now have features designed to take advantage of television and movie content. Some include TV tuners and connectors for video signals from cable television systems or antennas. Many new monitors are simply HDTVs in disguise.
Image Quality
What to look for:
Office work/Web surfing
Inspecting
A few tips on how to look for what you want.
Viewing angle: Look at the monitor from different angles and be aware of how much the colors shift or if the screen darkens. Also, pay attention to the angle when the screen begins to look different. Colors and brightness should not change when viewing the screen from an off angle, either from the sides, top, or below. TN panels will be the most egregious offender.
Text: Go to a Web site and scrutinize the legibility of small text. Firefox lets you change the font size from its options menu. Also, be aware of any color tint problems when viewing black text on a white background
Accurate colors: View something on the monitor you're familiar with, like a digital photo of a loved one or colleague you see every day and notice how different the colors in the picture look from the monitor.
Glossy screens can seemingly increase the contrast of movies and games. Some don't appreciate the extreme reflectiveness, however. View both glossy and matte screens and decide which looks better to you.
Low black level: The closer a monitor can get to displaying black, the better. True black is illusive and the most you can hope for is that a monitor displays very dark gray. Check out dark scenes in movies and notice how dark the black gets without actually losing the detail of a scene.
An adequate graphics card is a necessity
What's going on inside your computer can have a profound effect on what's displayed on your monitor. If you hook up a 4- or 5-year-old PC to a top-of-the-line new monitor, there's a good chance your graphics card will need an upgrade to give you the best possible image quality. You'll need a card that supports your interface, be it DVI or HDMI, and it will need to support your monitor's resolution--this is especially important on 30-inch models with 2,560x1,600-pixel resolutions. Sometimes, improving your graphics card's performance can be as easy as installing a driver upgrade from the manufacturer's Web site.
Office work/Web surfing
- Good text reproduction
- High brightness
- No ghosting during fast gameplay
- No delay in onscreen action after entering a command
- Low black level
- Wide viewing angle
- Accurate colors
- Accurate colors
- Good viewing angle
Inspecting
A few tips on how to look for what you want.
Viewing angle: Look at the monitor from different angles and be aware of how much the colors shift or if the screen darkens. Also, pay attention to the angle when the screen begins to look different. Colors and brightness should not change when viewing the screen from an off angle, either from the sides, top, or below. TN panels will be the most egregious offender.
Text: Go to a Web site and scrutinize the legibility of small text. Firefox lets you change the font size from its options menu. Also, be aware of any color tint problems when viewing black text on a white background
Accurate colors: View something on the monitor you're familiar with, like a digital photo of a loved one or colleague you see every day and notice how different the colors in the picture look from the monitor.
Glossy screens can seemingly increase the contrast of movies and games. Some don't appreciate the extreme reflectiveness, however. View both glossy and matte screens and decide which looks better to you.
Low black level: The closer a monitor can get to displaying black, the better. True black is illusive and the most you can hope for is that a monitor displays very dark gray. Check out dark scenes in movies and notice how dark the black gets without actually losing the detail of a scene.
An adequate graphics card is a necessity
What's going on inside your computer can have a profound effect on what's displayed on your monitor. If you hook up a 4- or 5-year-old PC to a top-of-the-line new monitor, there's a good chance your graphics card will need an upgrade to give you the best possible image quality. You'll need a card that supports your interface, be it DVI or HDMI, and it will need to support your monitor's resolution--this is especially important on 30-inch models with 2,560x1,600-pixel resolutions. Sometimes, improving your graphics card's performance can be as easy as installing a driver upgrade from the manufacturer's Web site.
Monitor Warranties
When choosing a monitor, consider the company behind it.
First and foremost, make sure that the company offers a money-back guarantee. Most displays will show its problems right out of the box or within the first month or two of use, so you want to be able to return it for a refund or an exchange with a minimum of hassle. A 90-day return policy is standard, but this varies among retailers (many online retailers give you only 30 days). Also, beware of restocking fees.
Next, consider the warranty coverage. Most companies offer two to three years of parts-and-labor coverage; anything less is suspect. Make sure that the backlight is covered by the warranty; manufacturers used to exclude them from coverage, but more and more now include them. Also note a company's policy on defective pixels; one or two defects are to be expected, but if there are many, you should be able to return the unit for exchange or a refund. Some companies deal with pixel problems on a "case-by-case" basis, meaning that they don't have a set policy. If you end up with a problematic display, you'll have to negotiate with the company. This is where the satisfaction-guaranteed return policy can become very important.
You're far less likely to need technical support for a monitor than for a computer system or a software program. Still, it's good to know that there's someone you can call if trouble arises; look for toll-free support numbers and weekend coverage.
Be sure to keep all of the packing material for your monitor. If you should ever need to return it or ship it back for warranty service, you'll need the packaging. Monitors can be bulky, fragile, and extremely difficult to protect adequately. You don't want to end up improvising when shipping it.
First and foremost, make sure that the company offers a money-back guarantee. Most displays will show its problems right out of the box or within the first month or two of use, so you want to be able to return it for a refund or an exchange with a minimum of hassle. A 90-day return policy is standard, but this varies among retailers (many online retailers give you only 30 days). Also, beware of restocking fees.
Next, consider the warranty coverage. Most companies offer two to three years of parts-and-labor coverage; anything less is suspect. Make sure that the backlight is covered by the warranty; manufacturers used to exclude them from coverage, but more and more now include them. Also note a company's policy on defective pixels; one or two defects are to be expected, but if there are many, you should be able to return the unit for exchange or a refund. Some companies deal with pixel problems on a "case-by-case" basis, meaning that they don't have a set policy. If you end up with a problematic display, you'll have to negotiate with the company. This is where the satisfaction-guaranteed return policy can become very important.
You're far less likely to need technical support for a monitor than for a computer system or a software program. Still, it's good to know that there's someone you can call if trouble arises; look for toll-free support numbers and weekend coverage.
Be sure to keep all of the packing material for your monitor. If you should ever need to return it or ship it back for warranty service, you'll need the packaging. Monitors can be bulky, fragile, and extremely difficult to protect adequately. You don't want to end up improvising when shipping it.
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