Plasma vs. LCD vs. LED TV
Which delivers the best TV picture for home entertainment?
Comparative Guide (2): Picture Quality Issues
In this second part of our plasma versus LCD and LED TV comparative guide, we discuss how the different display technologies impact the most important deliverable of any HDTV: the picture.
Surely, a different technology is driving the end result. In an ideal world, choosing your HDTV should not be a technology issue, but in real life the technology behind the screen has its impact on the resultant picture quality, so...
How do the different display technologies impact the resultant TV picture? Are there any major differences between the different flat-panel TV technologies with respect to contrast ratio, black level performance, color accuracy, viewing angle, supported picture detail, picture uniformity, etc.? And what about the latest 3D TVs—is there a display technology capable of delivering a better 3D picture than the rest?
Panasonic VIERA 55-inch TC-P55ST60
...first HDTV to ever gain a 5-Star rating
in a Cnet review!
If the ST50 from 2012 did prove to be the HDTV to deliver the best value for your money, this new 2013 model from Panasonic turned out to be even better - delivering a picture you would generally expect from a more expensive flagship model.
Its 3D picture is not among the best, yet the ST60 is capable of amazing picture quality at a price that is well within reach of the average budget.
Contrast, Black Level, Color Accuracy, & Picture Uniformity
This is one of those areas in this plasma vs. LCD vs. LED TV technology war that is becoming increasingly difficult to determine where to go. The latest plasma and LCD TVs are both capable of an excellent picture with bright, crisp clear images.
Yet there remain a few significant differences when it comes to picture performance, differences that render one technology more suitable than the other under certain circumstances.
Black Level Performance:
Black level performance is a most important picture quality attribute. It helps render better those difficult-to-define quality aspects like picture depth, scene detail especially in scenes where lots of dark and light content is shown simultaneously, and color richness—i.e. the perceived color saturation. Indirectly, a better black level also leads to better rendering of picture contrast.
Plasma TV sets are generally more suitable for home theater use than LCD TVs, even though the latest LED TVs are capable of achieving exceptionally deep blacks. However, plasma TVs picture quality characteristics render plasma television sets more suitable for use under controlled lighting. The main reason is plasma's deeper blacks. The gas cell structure within a plasma display is such that there is no light leaking between adjacent pixels.
This enables a plasma TV to display deeper blacks than its LCD counterpart especially when handling mixed content images with predominantly dark areas but that still contains small bright parts to be displayed simultaneously over a dark background.
Many argue that LED TVs are also capable of dark blacks in comparison to CCFL LCD TVs, with a level of black that is in line with that of the best plasma TVs. This is true but the main problem with LED TVs arise when handling bright content over predominantly dark background; even the more precise LED TVs with full array local dimming are not capable of producing precise localized blacks in a similar manner to the best plasmas in these circumstances.
The nature of LCD technology where a backlight shines through the LCD layer makes it difficult to achieve true blacks, i.e. true absence of light. There is always some light leakage between adjacent picture elements in an LCD panel. And this applies even to the latest LED-backlit LCD TVs using the more expensive full local dimming technology.
The situation with edge-lit LED TVs is basically the same as that of CCFL LCD TVs; keep in mind that these are basically the standard LCD TV with the CCFL replaced by a LED backlight. Some of the best edge-lit LEDs are now using zone dimming technology to improve the black level performance over a wider range of picture content. However, the result is not as good as full array LED backlights with local dimming, and even more so than plasma TVs. The main advantage of edge-lit LED TVs over CCFL LCDs is that LED TVs can switch the LED backlight off to achieve total darkens say between scenes. But their overall black level performance with mixed content nowhere approaches that of the best plasma TVs.
Instead, the darkest parts of an image on a plasma TV can be as dark as a fraction of a candela. This corresponds to the 'brightness' of the turned-off phosphor. In the case of an LCD television, the 'brightness level' of the darkest picture scenes is significantly higher; in the worst case, it can even reach one candela - at times even more, and this when viewed just right in front of the LCD display. View the LCD or LED TV screen at an angle, and you will find that its black level performance deteriorates significantly. As stated, LED TVs can achieve total darkens by switching the LED backlight off but you cannot take black level on its own; more important than the deepest black a TV can achieve is the overall black level performance with mixed content.
In other words, when it comes to plasma vs. LCD vs. LED TV, despite the latest improvements in LED TV technology, plasma still enjoys a technological advantage.
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If you want to enjoy the most natural colors, the best plasma televisions delivers better but the difference between high-end models for both display technologies is just a hair apart often noticeable only under a test environment. This slight plasma edge arises out of the way color is produced in LCD displays where white light from the backlit source is filtered through micro color filters build in sub-pixels.
This LCD light transmissive method (applicable to both CCFL and LED LCD TVs) of controlling color makes it inherently difficult to maintain color accuracy and vibrancy even though most LCD displays manage to do quite an impressive job. Instead, plasma generates color direct at the light source thanks to the different phosphors used in the individual sub-pixel elements.
In general, plasma displays continue to exhibit more richness in color information and more natural coloration; on the other hand, LCD display panels tend towards over-saturation. This over-saturation and their relatively brighter image render LCD panels more suitable for use in brightly lit environments even though one still has to be careful with the positioning of your light sources with LCD TVs using a shiny screen to avoid glare issues.
This does not mean LCD panels are not suitable for use in the home theater. Some of the latest generation LCD TVs with intelligent backlight units are capable of delivering even greater color freedom, thus yielding more true to life colors. In particular, the latest developments in LCD panel backlights using LED light are capable of accurate rendering of color detail.
We are seeing some really high contrast ratio ratings for both plasma and LCD TVs, and especially LED TVs, with the latest trend being the popular mega-contrast ratings.
Yet when it comes to comparing plasma vs. LCD vs. LED TV contrast performance, the real problem with LCD (and LED) televisions is not insufficient contrast with respect to plasma TVs. Rather, it is the deterioration in picture quality associated with LCDs due to a noticeable lowering in contrast and black levels with off-axis viewing; this also leads to loss of color saturation. This is not the case with plasma TVs.
A word of caution here about high contrast ratio ratings:
Manufactures like to impress with big numbers. However, keep in mind it is not possible for the human eye to perceive any difference between a contrast ratio of say 5,000:1 and 10,000:1. In addition, static (or on-screen contrast) and dynamic contrast ratings are not one and the same thing. Manufacturers tend to quote the latter as it yields a much bigger number.
The perceived contrast level by the eye depends on a number of factors. Apart from the level of ambient, in the case of direct-view displays like plasma and LCD, contrast ratio performance is also dependent on the effectiveness of the screen anti-glare filter in maintaining black levels under bright lighting—more specifically in its effectiveness to block external light from entering the display panel.
For more information on this issue, please refer to our Contrast Ratio article.
Image uniformity encompasses a number of aspects that range from uniformity of the image brightness across the screen to image smoothness. These are issues that are highly dependent on the display technology. But quite a few of these uniformity issues may arise out of problems with the video processing itself and therefore, may vary significantly between brands.
When comparing plasma vs. LCD image uniformity performance, plasma enjoys a definite edge over LCD and LED TVs. In particular, plasma seems to be more forgiving when displaying noisy video content. In a similar manner, shadow gradations on plasma looks smoother than on an LCD.
Problems related to lack of uniformity in image brightness across the entire screen are exclusively LCD related. LCDs often exhibit brighter spots; how pronounced varies from make to make, but in general, brightness is not 100% uniform across an LCD or LED TV screen, mainly because of problems with the backlight-diffuser system used to spread light across the full display area. With edge-lit LED TVs, screen uniformity is often worse than with CCFL LCD TVs. This is not the case with plasma TVs.
Issues such as banding, clouding, and pillaring are all forms of uniformity issues associated with problems in the LCD backlight. These problems may arise with both CCFL-based LCDs and edge-lit LED backlights. Additionally, LED LCDs using local dimming technology may also exhibit a halo effect (or blooming) when displaying bright objects over a predominantly dark background.
These brightness uniformity issues in LCDs are further pronounced with off-angle viewing.
3D Picture Quality
Plasma and LCDs (CCFL and LEDs) do not perform the same when displaying 3D content. Again, it is plasma that takes the upper hand here. It seems that unlike plasma TVs, CCFL and LED LCD televisions are more prone to image crosstalk. The latter is a phenomenon in 3D viewing where a subtle washed-out image intended for the right eye appears as a halo around the image intended for the left eye and vice versa. This subtle double image effect may at times become annoying with some 3D content to the point that it may even cause eye fatigue.
3D crosstalk can be caused by a variety of factors that are not display dependent but 3D image crosstalk is also enhanced by an insufficient pixel response time. Even the latest superfast (for an LCD) 1msec response time quoted by some LED TV makers is not fast enough to eliminate crosstalk completely. Rather, the latest 3D plasma HDTVs continues to fair better in professional reviews when it comes to 3D picture performance - often delivering a 3D picture with hardly any visible crosstalk.
But it is not just 3D image crosstalk... LCD and LED display panels have another drawback when it comes to 3D TVs! Because of the polarizer layer used on LCD panels (both on the TV display and the 3D glasses), the viewer has to sit in an upright position to get the best 3D effect; try to tilt or relax and sit back with the glasses at an angle to the LCD screen and the image would go dark as the polarization of the display panel and that of the glasses cross each other.
Plasma vs. LCD vs. LED - Picture Quality ADVANTAGE:
Here our thumbs up in this plasma vs. LCD analysis go to plasma televisions, even though both technologies are extremely close in terms of overall picture performance. However, plasma color richness and naturalness will prevail in most environments. Plasma also performs better when it comes to 3D TV due to its less susceptibility to 3D image crosstalk.
Earlier on in this discussion, we referred to the relatively brighter image of LCD TVs. The latest energy efficient plasma display panels from Samsung, Panasonic, and LG are also capable of producing relatively very bright images despite the new low power consumption levels of the latest plasma HDTVs. This makes the latest plasma TVs equally suitable for use in brightly lit rooms. However...
Plasma vs. LCD vs. LED Bright Room Advantage
LCDs will generally perform better in brightly lit rooms due to their inherent anti-glare technology and higher brightness levels.
In addition, we still recommend using LCDs (and LED TVs) under bright lighting instead of plasma. Apart from plasma's higher power consumption levels to produce the brighter picture in comparison with CCFL LCD and even more so LED TVs, prolonged use of high brightness levels in plasma displays may eventually reduce the plasma phosphor lining performance.
Plasma vs. LCD: Viewing-angle
In this plasma vs. LCD discussion, we continue by looking at how picture quality behaves with a change in viewing angle. We have already touched upon this issue earlier on in this article. The viewing angle represents how far one can sit on either side of the screen away from the center, without experiencing significant deterioration in picture quality mainly because of color shifts and reduced contrast.
Plasma televisions typically have a better viewing angle than LCD TVs as they hold black levels much better with off-axis viewing than LCDs. This usually occurs at around 100 degrees, i.e. at some 50 degrees on either side of a line drawn normal to the center of the screen.
The main reason for this plasma advantage is that each pixel in a plasma display panel produces its own light rather than having light being spread across the screen from one central backlight source and then controlled by active polarized elements in the display panel. Hence, each pixel is more readily visible even when viewing at an angle to the screen surface because its brightness is consistent with every other pixel on the screen.
Recent developments in LCD technology mean this is less of an issue especially with the latest generation of CCFL LCD televisions. LED TVs still suffer from a somewhat more restricted viewing angle than their CCFL counterparts. But in either case, with LCD TVs you have to take the best seat to enjoy the best picture.
Plasma vs. LCD - Viewing Angle ADVANTAGE:
What used to be a clear advantage for plasma displays is becoming more and more a non-issue especially with the latest generation of LCD televisions, however...
Do not always assume that viewing angle is no longer important when comparing plasma vs. LCD or LED TVs, especially if the viewing angle is not specified. The tendency in particular with cheaper LCD TV sets is that the deterioration in picture quality is more accentuated with LCD and in particular LED TVs than with plasma televisions.
TV Viewing distance
The minimum recommended viewing distance for a 1080p HDTV is approximately twice the screen width. Yet, due to the different pixel structure between plasma and LCDs, if your viewing distance is restricted to around 6 to 8 feet, probably you will be better off with an LCD TV. The pixel-display build up structure of an LCD and LED TVs helps render a smoother picture than that from equivalent size plasma TV for the same pixel count at closer viewing distances.
For more information on TV viewing distance considerations, please refer to our article here.
Plasma vs. LCD vs. LED - Viewing Distance ADVANTAGE:
None if you are within normal viewing distance for your screen size; this applies as long as your viewing distance is more than approximately 6 to 8 feet away from the TV screen. If you have a too short TV viewing distance, an LCD or LED television may render itself better as its pixel structure is less visible.
Up to not long ago, LCD panels used to deliver more in terms of pixel count. LCD manufacturers were also the first to come with 1080p HDTVs; this was also used to a great extent by LCD TV retailers as a sales advantage over plasma TVs. This is no longer the case; for anything greater and including 42-inch screens, plasma TVs are readily available in 1080p full HD resolution. This means that the two display technologies are now on par in this respect.
Rather present HDTV lineups are such that you have more choice for 1080p HDTVs irrespective of display technology; additionally, 720p LCD and LED TVs at anything bigger than 32-inch have become almost inexistent, while in the case of plasma, it is still possible to find a few budget-class 720p HDTVs at the 42-inch and 50-inch category.
A word of caution: Do not underestimate the picture quality supported by the less expensive 720p display. Keep in mind that the eye would not be able to perceive the additional picture detail afforded by the 1080p pixel count for screens less than and including 50-inch diagonals from what is considered normal viewing distance; this being especially so with HD TV program content. Opting for a 720p instead of a 1080p HDTV at this screen size would generally lead to marginal savings over corresponding entry-level 1080p HDTVs.
Plasma vs. LCD vs. LED - Picture Resolution ADVANTAGE:
At screen sizes where collision between the two technologies occurs, plasma and LCD TVs are both available in 1080p resolutions. Rather, when comparing plasma vs. LCDs, the real problem for the HDTV buyer is that 720p LCD TVs are no longer available within the 40-inch to 50-inch screen category.
Buying Options for Plasma and LED HDTVs
Amazon.com offers an extensive range of HDTVs, often at significantly reduced prices. While at amazon...
Check the customer feedback to see what others had to say for a better insight about the product and customer experience.