There are many different panel technologies used in the production of LCD monitors. They range from budget TN panels to expensive, professional quality S-IPS and S-PVA panels. The average consumer usually has no idea what panel technology is used in their LCD. In fact, many power users are also unaware, simply because the panel type is rarely listed by the manufacturer in the monitor specifications. Many users buy monitors based on price and size. Price should be a factor, but you should still know the advantages and disadvantages of the different LCD panel types and be able to identify them before you decide which LCD to purchase.
S-IPS Panel Technology
S-IPS panels are generally considered the best overall LCD technology for image quality, color accuracy and viewing angles, but this comes at a price. They are well suited for graphics design and other applications which require accurate and consistent color reproduction. S-IPS panels offer the best viewing angles of any current LCD technology, with wide viewing angles up to 178 degress. VA panels can also have specs as high as 178 degress, but many suffer from a loss of contrast around 165-170 degrees. The response time of S-IPS is adequate, ranging from 6ms to 16ms with current panels. This is only slightly slower than TN panels. However, gamers should take this into consideration. Fast paced games may suffer from motion blur or ghosting with S-IPS panels that have a response time higher than 8ms. S-IPS panels can be identified buy a slight purple hue on blacks when viewed from a wide angle. There are currently few manufacturers using S-IPS panels in comparison to the other panels types making choices limited and they often carry a premium price tag.
Two of the most popular widescreen S-IPS monitors are the NEC 20WMGX2 and Dell 2007WFP. The NEC 20WMGX2 monitor uses an AS-IPS panel (basically a custom S-IPS panel made specifically for NEC), has a 6ms response time, glossy coating and includes a TV tuner and speaker bar. The price of the 20WMGX2 ranges from $500-$600. The Dell 2007WFP is much more affordable at around $350, but you are not guranteed an S-IPS panel and it has less features. Unfortunately Dell uses two panel types in this monitor. S-IPS and S-PVA. It is a completely random process so there is no way to know which panel you will receive. However, due to the much lower price of the 2007WFP many are willing to take the risk for a cheap widescreen S-IPS panel.
VA Panel Technology
S-PVA and MVA panels are middle of the road panels. They offer better color reproduction and wider viewing angles than TN panels, but have slower response times. They are very similar to S-IPS on paper. They also offer large viewing angles and good color reproduction, though not as good as S-IPS. The response times are generally worse than TN or S-IPS panels and there have been reports of a few monitors with VA panels that suffer from input lag, so they may not be the best choice for gaming. S-PVA has the advantage of higher contrast ratios than the other panel types which leads to better black levels. The biggest disadvantage of S-PVA panels is color shifting. Color shifting is when the image from one angle changes or "shifts" when viewed from another angle. This bothers many users to the point they will not even consider buying an S-PVA panel, while others don't even notice the color shifts. Color shifts also cause a loss of shadow detail in dark scenes when viewed directly from the center. Prices on S-PVA panels are around the same or slightly cheaper than S-IPS panels, but they are much easier to find as many manufacturers use S-PVA panels. Also, almost all monitors in the popular 24" category use S-PVA panels.
TN Panel Technology
TN panels are the most widely used panel type as they are cheap and offer excellent response times, making them perfect for fast paced gaming. The response times of current TN panels range from 2ms to 5ms. However, color reproduction, viewing angles and contrast ratios of TN panels are the worst of any LCD panel technology. Unlike most 8-bit S-IPS/S-PVA/MVA panels, TN panels are only 6-bit and unable to display the full 16.7 million colors available in 24-bit true color. They can mimick the 16.7 million colors of 8-bit panels using a technique called dithering, but the results are unimpressive. TN panels have become popular with the average user because they are very inexpensive. They are also the only panels currently being used in 22" widescreen monitors, a very popular size. Many of these 22" TN panels are around the same price or cheaper than other 20" monitors with different panel types, so it is easy to see how how they gained popularity. Afterall, the average user buys a monitor based on price and size.
Summary of LCD Panel Technology
S-IPS panels are generally considered the best all around panel type, but they are more expensive and very few are made.
S-PVA/MVA panels offer better color reproduction and viewing angles than TN panels, have slightly worse response times than TN or S-IPS, offer the best contrast ratios, may suffer from color shifting or input lag and have higher availability than S-IPS panels.
TN panels are very cheap with fast response times but have inferior color reproduction, contrast ratios and viewing angles. Only panel type currently available in 22" size.
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Backlight Bleeding: An LCD Problem
The entire surface of an LCD is backlit from behind by a light source (CCFL light) and the LCD blocks out the light that is not needed. Backlight bleeding occurs when this light is not 100% blocked allowing some light to "bleed" through the LCD causing spots of lighter areas on a dark or black background. Unfortunately, almost all LCDs suffer at least a small amount of backlight bleed because the opacity of LCD panels is not enough to block all light, though it only causes problems if it can be easily detected by the human eye. The graphic to the right (check plaatje beneden) shows an example of what an LCD display with excessive backlight bleeding looks like with a dark, static background. As you can see, the top left and bottom right corner are lighter in color than the center of the display.
Fixing Backlight Bleed
In general, there is no definite fix for backlight bleeding, although some users in this thread ( http://www.hardforum.com/showthread.php?t=1032268 ) have had success improving the bleeding on the model 2005FPW Dell LCD using the method listed. The best way to fix backlight bleed is to have the monitor replaced or avoid LCD's which are known to have bleeding problems all together. Read reviews on the model of LCD you plan on purchasing, buy from a retailer that will allow you to exchange the display if there are any major problems and if possible try to view a display model or two before you buy. Even this does not guarantee you will receive an LCD completely free from bleeding.
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Source: www.pchardwarehelp.com
S-IPS Panel Technology
S-IPS panels are generally considered the best overall LCD technology for image quality, color accuracy and viewing angles, but this comes at a price. They are well suited for graphics design and other applications which require accurate and consistent color reproduction. S-IPS panels offer the best viewing angles of any current LCD technology, with wide viewing angles up to 178 degress. VA panels can also have specs as high as 178 degress, but many suffer from a loss of contrast around 165-170 degrees. The response time of S-IPS is adequate, ranging from 6ms to 16ms with current panels. This is only slightly slower than TN panels. However, gamers should take this into consideration. Fast paced games may suffer from motion blur or ghosting with S-IPS panels that have a response time higher than 8ms. S-IPS panels can be identified buy a slight purple hue on blacks when viewed from a wide angle. There are currently few manufacturers using S-IPS panels in comparison to the other panels types making choices limited and they often carry a premium price tag.
Two of the most popular widescreen S-IPS monitors are the NEC 20WMGX2 and Dell 2007WFP. The NEC 20WMGX2 monitor uses an AS-IPS panel (basically a custom S-IPS panel made specifically for NEC), has a 6ms response time, glossy coating and includes a TV tuner and speaker bar. The price of the 20WMGX2 ranges from $500-$600. The Dell 2007WFP is much more affordable at around $350, but you are not guranteed an S-IPS panel and it has less features. Unfortunately Dell uses two panel types in this monitor. S-IPS and S-PVA. It is a completely random process so there is no way to know which panel you will receive. However, due to the much lower price of the 2007WFP many are willing to take the risk for a cheap widescreen S-IPS panel.
VA Panel Technology
S-PVA and MVA panels are middle of the road panels. They offer better color reproduction and wider viewing angles than TN panels, but have slower response times. They are very similar to S-IPS on paper. They also offer large viewing angles and good color reproduction, though not as good as S-IPS. The response times are generally worse than TN or S-IPS panels and there have been reports of a few monitors with VA panels that suffer from input lag, so they may not be the best choice for gaming. S-PVA has the advantage of higher contrast ratios than the other panel types which leads to better black levels. The biggest disadvantage of S-PVA panels is color shifting. Color shifting is when the image from one angle changes or "shifts" when viewed from another angle. This bothers many users to the point they will not even consider buying an S-PVA panel, while others don't even notice the color shifts. Color shifts also cause a loss of shadow detail in dark scenes when viewed directly from the center. Prices on S-PVA panels are around the same or slightly cheaper than S-IPS panels, but they are much easier to find as many manufacturers use S-PVA panels. Also, almost all monitors in the popular 24" category use S-PVA panels.
TN Panel Technology
TN panels are the most widely used panel type as they are cheap and offer excellent response times, making them perfect for fast paced gaming. The response times of current TN panels range from 2ms to 5ms. However, color reproduction, viewing angles and contrast ratios of TN panels are the worst of any LCD panel technology. Unlike most 8-bit S-IPS/S-PVA/MVA panels, TN panels are only 6-bit and unable to display the full 16.7 million colors available in 24-bit true color. They can mimick the 16.7 million colors of 8-bit panels using a technique called dithering, but the results are unimpressive. TN panels have become popular with the average user because they are very inexpensive. They are also the only panels currently being used in 22" widescreen monitors, a very popular size. Many of these 22" TN panels are around the same price or cheaper than other 20" monitors with different panel types, so it is easy to see how how they gained popularity. Afterall, the average user buys a monitor based on price and size.
Summary of LCD Panel Technology
S-IPS panels are generally considered the best all around panel type, but they are more expensive and very few are made.
S-PVA/MVA panels offer better color reproduction and viewing angles than TN panels, have slightly worse response times than TN or S-IPS, offer the best contrast ratios, may suffer from color shifting or input lag and have higher availability than S-IPS panels.
TN panels are very cheap with fast response times but have inferior color reproduction, contrast ratios and viewing angles. Only panel type currently available in 22" size.
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Backlight Bleeding: An LCD Problem
The entire surface of an LCD is backlit from behind by a light source (CCFL light) and the LCD blocks out the light that is not needed. Backlight bleeding occurs when this light is not 100% blocked allowing some light to "bleed" through the LCD causing spots of lighter areas on a dark or black background. Unfortunately, almost all LCDs suffer at least a small amount of backlight bleed because the opacity of LCD panels is not enough to block all light, though it only causes problems if it can be easily detected by the human eye. The graphic to the right (check plaatje beneden) shows an example of what an LCD display with excessive backlight bleeding looks like with a dark, static background. As you can see, the top left and bottom right corner are lighter in color than the center of the display.
Fixing Backlight Bleed
In general, there is no definite fix for backlight bleeding, although some users in this thread ( http://www.hardforum.com/showthread.php?t=1032268 ) have had success improving the bleeding on the model 2005FPW Dell LCD using the method listed. The best way to fix backlight bleed is to have the monitor replaced or avoid LCD's which are known to have bleeding problems all together. Read reviews on the model of LCD you plan on purchasing, buy from a retailer that will allow you to exchange the display if there are any major problems and if possible try to view a display model or two before you buy. Even this does not guarantee you will receive an LCD completely free from bleeding.
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Source: www.pchardwarehelp.com