Shopping for an LCD HDTV?
Know Your Stuff!!
What's LCD HDTV?
Much like other LCD devices you're more used to, such as alarm clocks and computer monitors - LCD televisions also utilize a technology based on polarized light, where two polarized panels are located in front of and in back of a thin layer of liquid crystal gel, that is divided up into individual pixels. Each pixel is activated individually thanks to two axis of wires, which polarizes them accordingly.
"Ghosting" used to be a noticeable problem with older model LCDs. It's a term that describes how certain bright parts of a movie would "hang around" for a few seconds, or even display a trail as it moved across the screen. This is due to brighter pixels that would 'maintain' light for a time period of 20 milliseconds, while undergoing the transition to another color or light intensity for another 15-20 milliseconds of time. Since the inception of LCD televisions, that time was shortened to only 8 milliseconds.
In order to improve the quality of LCD televisions going forward, a viable strategy is to increase the refresh rate (the 'invisible' line that scrolls and refreshes the screen constantly), and to reduce the backlight response of the LCD screen itself.
Interlaced vs. Progressive LCD HDTVs
Another factor in LCD HDTVs are the scan rate: which include an interlaced and a progressive picture. Have you ever seen video tape footage of a PC screen? If so, you may have noticed how the screen seems to "sweep" up and down constantly, almost like a slide show. That is an interlaced picture. Similarly, interlaced HDTVs (and monitors) refresh every other line of the picture, every other time. The process is unseen by the naked eye. However, interlaced screens are known to cause "eye distress," which your mother warned you about when you sat too close to the TV set. Progressive sets, on the other hand, refresh every line every single time, much like one long "sweep" down the screen after another. Progressive pictures are easier on the eyes, display a smooth viewing image with less "jaggies," and consequentially, cost a little more.
What is DLP HDTV?
DLP or "Digital Light Processing" is a rear projection technology for television. DLP HDTVs are typically less expensive and more lightweight that LCD or Plasma TVs, immune from screen burn-in & color decay, and able to represent high speed images without ghosting or blurring effects that other television technologies suffer from. DLP TVs are known to have excellent color and grayscale representation. LED DLP TVs never need a lamp replacement. Note that non-LED DLP's (typically older models, as most today are LED) *will* need lamp replacements after several years of usage, and the cost can be rather high. Overall, an LED DLP HDTV is a worthy investment for its long life, great color quality and slim size. Avoid older DLP HDTVs, as they're known to suffer from a condition known as the "rainbow effect," in which bright white tones projected over black backgrounds appear in a multi-color effect. Newer televisions do not have this issue.
LCD HDTV Aspect Ratio
You may have already seen terms here, such as "16:9 aspect ratio," and had no clue what it meant. Aspect ratio simply means "units high x units wide." So, a 16:9 HDTV is 16 units wide x 9 units high ("units" meaning the measurement of an original video production, a broadcasting term). Wide sets allow you to see widescreen movies in their "natural mode," without the letterbox crop bars. They also allow you to watch the older, non-narrow shows as well, albeit with the black crop bars on the left and right. Overall, the newer, wider 16:9 is the winner over the older 4:3 "standard" television screens for their breadth of view, and ability to watch older formats, as well!
What Does "720" or "1080" HDTV Mean?
HDTVs are always defined by the resolution, or the number of vertical pixels that they have. For instance, a 720 HDTV has 720 pixels per line going up and down (rather, vertically) the screen itself, and across 1,280 lines going horizontally to the other end of the screen. In contrast, a 1080 HDTV has 1080 pixels per line going vertically, with 1,920 lines going across, horizontally. In these cases, the 1080 HDTV set is the better of the two - since more pixels means more detail. Note that the resolution and the actual size of the screen in inches are not directly related: therefore, a 22" 1080p HDTV and a 22" 720p HDTV can both exist (don't assume that smaller screens are always 720p!)
1080p vs. 1080i HDTV...Which One Wins?
Naturally, you'll want to go with the best option for the most technologically long-lasting, satisfying, high quality LCD television set; especially in a consumer market where things keep changing so rapidly.
The question of 1080p and 1080i comes up in this case. What does it mean? In short, these are two popular HDTV video modes found in the newer model TV sets. 1080"p" represents "Progressive Scan." This means that the pictures on a 1080p television screen are drawn with a moving line, similarly to the way computer monitors work.
Conclusively: the 1080p HDTV is the superior product, although it is the more expensive choice. If you're going for a somewhat larger screen, you'll appreciate the 1080p's progressive nature. It's always best practice to go with the "newer" format; which in this case, is the 1080p.
There is one important thing to mention here: if you're going for larger screens, there's no doubt that you should only consider a 1080p...however, if your screen is 50" or less, there will be no visible difference with the additional pixels that come with the 1080p. So, stick with a 720p for a screen that's 50" or less -- you'll save a lot of money without sacrificing quality.
Let's review the pros and cons of the 1080p, vs. that of the older 1980i format. Despite the fact that 1080i has its own set of proficiencies, the 1080p is the superior technology:
1080p HDTV Pros (vs. 1080i)
1080p HDTV Cons (vs. 1080i)
"Ghosting" used to be a noticeable problem with older model LCDs. It's a term that describes how certain bright parts of a movie would "hang around" for a few seconds, or even display a trail as it moved across the screen. This is due to brighter pixels that would 'maintain' light for a time period of 20 milliseconds, while undergoing the transition to another color or light intensity for another 15-20 milliseconds of time. Since the inception of LCD televisions, that time was shortened to only 8 milliseconds.
In order to improve the quality of LCD televisions going forward, a viable strategy is to increase the refresh rate (the 'invisible' line that scrolls and refreshes the screen constantly), and to reduce the backlight response of the LCD screen itself.
Interlaced vs. Progressive LCD HDTVs
Another factor in LCD HDTVs are the scan rate: which include an interlaced and a progressive picture. Have you ever seen video tape footage of a PC screen? If so, you may have noticed how the screen seems to "sweep" up and down constantly, almost like a slide show. That is an interlaced picture. Similarly, interlaced HDTVs (and monitors) refresh every other line of the picture, every other time. The process is unseen by the naked eye. However, interlaced screens are known to cause "eye distress," which your mother warned you about when you sat too close to the TV set. Progressive sets, on the other hand, refresh every line every single time, much like one long "sweep" down the screen after another. Progressive pictures are easier on the eyes, display a smooth viewing image with less "jaggies," and consequentially, cost a little more.
What is DLP HDTV?
DLP or "Digital Light Processing" is a rear projection technology for television. DLP HDTVs are typically less expensive and more lightweight that LCD or Plasma TVs, immune from screen burn-in & color decay, and able to represent high speed images without ghosting or blurring effects that other television technologies suffer from. DLP TVs are known to have excellent color and grayscale representation. LED DLP TVs never need a lamp replacement. Note that non-LED DLP's (typically older models, as most today are LED) *will* need lamp replacements after several years of usage, and the cost can be rather high. Overall, an LED DLP HDTV is a worthy investment for its long life, great color quality and slim size. Avoid older DLP HDTVs, as they're known to suffer from a condition known as the "rainbow effect," in which bright white tones projected over black backgrounds appear in a multi-color effect. Newer televisions do not have this issue.
LCD HDTV Aspect Ratio
You may have already seen terms here, such as "16:9 aspect ratio," and had no clue what it meant. Aspect ratio simply means "units high x units wide." So, a 16:9 HDTV is 16 units wide x 9 units high ("units" meaning the measurement of an original video production, a broadcasting term). Wide sets allow you to see widescreen movies in their "natural mode," without the letterbox crop bars. They also allow you to watch the older, non-narrow shows as well, albeit with the black crop bars on the left and right. Overall, the newer, wider 16:9 is the winner over the older 4:3 "standard" television screens for their breadth of view, and ability to watch older formats, as well!
What Does "720" or "1080" HDTV Mean?
HDTVs are always defined by the resolution, or the number of vertical pixels that they have. For instance, a 720 HDTV has 720 pixels per line going up and down (rather, vertically) the screen itself, and across 1,280 lines going horizontally to the other end of the screen. In contrast, a 1080 HDTV has 1080 pixels per line going vertically, with 1,920 lines going across, horizontally. In these cases, the 1080 HDTV set is the better of the two - since more pixels means more detail. Note that the resolution and the actual size of the screen in inches are not directly related: therefore, a 22" 1080p HDTV and a 22" 720p HDTV can both exist (don't assume that smaller screens are always 720p!)
1080p vs. 1080i HDTV...Which One Wins?
Naturally, you'll want to go with the best option for the most technologically long-lasting, satisfying, high quality LCD television set; especially in a consumer market where things keep changing so rapidly.
The question of 1080p and 1080i comes up in this case. What does it mean? In short, these are two popular HDTV video modes found in the newer model TV sets. 1080"p" represents "Progressive Scan." This means that the pictures on a 1080p television screen are drawn with a moving line, similarly to the way computer monitors work.
Conclusively: the 1080p HDTV is the superior product, although it is the more expensive choice. If you're going for a somewhat larger screen, you'll appreciate the 1080p's progressive nature. It's always best practice to go with the "newer" format; which in this case, is the 1080p.
There is one important thing to mention here: if you're going for larger screens, there's no doubt that you should only consider a 1080p...however, if your screen is 50" or less, there will be no visible difference with the additional pixels that come with the 1080p. So, stick with a 720p for a screen that's 50" or less -- you'll save a lot of money without sacrificing quality.
Let's review the pros and cons of the 1080p, vs. that of the older 1980i format. Despite the fact that 1080i has its own set of proficiencies, the 1080p is the superior technology:
1080p HDTV Pros (vs. 1080i)
- Simpy put, it's newer than 1080i. It will, in fact, eventually become the "standard."
- Has twice the resolution of a 1080i signal, technically capable of displaying every single pixel of an HD broadcast.
- Progressive TV sets (flat LCDs, Plasmas) are already progressive in nature, can use progressive scan as a default (no need to convert from another type).
- Conveys all "lines" in a single sweep, resulting in a smoother, crisper image
1080p HDTV Cons (vs. 1080i)
- Has half the frame rate of 1080i
- More expensive than 1080i sets
- The difference in resolution between 1080p and 1080i may not be seen by the naked eye, except on larger TV sets
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