What is HDTV?
The best way to explain HDTV is to compare it to what your used to now, which is your current television. Most likely your current tv set is the standard analog CRT or Cathode Ray Tube. Most standard tv sets have 525 scan lines for the image and around 500 dots or pixels per each horizontal line. This resolution is good for viewing analog signals but not as good as your computer monitor, for example. You computer monitor is most likely capable of at least 1024x768 pixels. That is a huge difference in quality of the viewable image. Tthe lowest resolution of an HDTV is 1280x720 pixels progressive. But most if not all HDTV sets today are capable of at least 1920x1080 interlaced.
You are probably wondering "ok what is this progressive and interlaced mumbo-jumbo?" These are the types of scanning system the set uses. In the US there are 30 frames of a video image shown per second to the viewer. In "Interlaced" format, the screen shows every odd line at one scan of the screen and follows that up with the even lines in a second scan. With this format the screen shows one half of the frame every sixtieth of a second. For smaller screens this is less noticeable. But, as screens get larger, the problem with interlacing the image is a flicker type effect. This may be more noticeable to some people and less to others. Progressive scanning shows the entire image every sixtieth of a second. This provides a much smoother picture. However the progressive format use slightly more bandwidth and at higher resolutions is usually more expensive.
The current formats used in HDTV are:
* 720p - 1280x720 pixels progressive
* 1080i - 1920x1080 pixels interlaced (most common)
* 1080p - 1920x1080 pixels progressive (usually more expense but becoming very popular)
There are several types of HDTV on the market today. The main types are as follows: 1) CRT Picture Tube - a higher resolution version of your standard television set. 2) Rear Projection TVs - gives a high quality image at much larger screen sizes. 3) LCD - gives a very clear image but usually at a much higher cost especially as the screen size increases. 4) LCD Projection - this is similar to regular LCD but the image is projected instead of using one LCD panel for the entire size of the screen. 5) DLP Projection - the newest type which uses a special chip with tiny mirrors that is projected giving a very brilliant crisp image even at large screen sizes.
For a more detail description and the pros and cons of each type, please click on the type you are interested in from the menu bar on the left. You will also find user reviews and buying guides for each type and model.
DTV vs EDTV vs HDTV
If you are subscribed to cable tv or use a satellite service, then you probably already have digital television or DTV. The largest difference between DTV and a standard analog signal is that the signal is digitally encoded. This means there will be no "snow" or interference artifacts in the image. The problem is that the signal is usually converted to an analog format to be compatible with your existing tv sets. Although much better than an analog signal to begin with, you could still get some interference.
Your DVD player is a good example of pure DTV. You probably notice how clear a DVD plays compared to an analog VHS VCR. While normal DTV is much better than what we have saw 10 years ago, it is lacking significantly compared to HDTV.
Most of today's DVD players are capable of progressive scan at a 480p resolution which is called Extended Definition Television or EDTV. This gives you a step up from standard DTV format and at a wider screen format (16x9) capabilities. While this gives a better quality and theater like image, it still does not compare to HDTV. Be careful when shopping for a widescreen HDTV and not to mix it up with EDTV. It does not mean you should avoid EDTV, which is much less expensive than HDTV, but you do not want to confuse the two.
HDTV is a format of DTV but at much higher resolutions. Most standard DTV signals use the normal television resolution of about 500x525 pixels which is quite small compared to the 1920x1080 pixels of most HDTV sets. The larger resolution will show much more detail and sharpness in the picture. In fact it is very life like. While even standard DTV will show a nice and clear image of say a news caster. You can tell the news caster is wearing a nice black suit. But imagine not only seeing the color of the suit but the actually lining and thread in the suit just like if you were standing right in front of him. This is what HDTV will bring to you.
Screen Size or Aspect Ratio
All TV sets come in two 'Aspect Ratios.' Aspect Ratio refers to the ratio between the horizontal (width) measurement and the vertical (height) measurement of the screen. A normal television has an aspect ratio of 4:3 which means it is 4 units wide by 3 units high. Although HDTV can come in this ratio, especially with CRT types, most use the 16:9 aspect ratio which is 16 units wide by 9 units high. This gives you the widescreen viewing just like in a movie theater.
A typical TV broadcast uses an aspect ratio of 1.37:1 which is 1.37 times as wide as it is high. This converts well to a standard television set which is 1.33:1 or a 4:3 aspect ratio. However, most theater movies are 1.85:1 or 2.35:1. To convert this to the 4:3 aspect ratio of a normal television set the image must be panned and scanned. This means the image must be cropped down to the 4.3 size of the screen eliminating part of every frame of the video or letterbox it which means to show the full image, but only in the middle of the screen, causing black bars at the top and bottom.
Most HDTV screens have a much wider aspect ratio of 16:9 (1.85:1). This is how it can display such a high resolution. Widescreen movies will not be panned and scanned so you get the full picture as if you were watching it at the theater. And even if the picture is in a 2.35:1 ratio, it will convert much better than on a 4:3 standard television set.
The best way to explain HDTV is to compare it to what your used to now, which is your current television. Most likely your current tv set is the standard analog CRT or Cathode Ray Tube. Most standard tv sets have 525 scan lines for the image and around 500 dots or pixels per each horizontal line. This resolution is good for viewing analog signals but not as good as your computer monitor, for example. You computer monitor is most likely capable of at least 1024x768 pixels. That is a huge difference in quality of the viewable image. Tthe lowest resolution of an HDTV is 1280x720 pixels progressive. But most if not all HDTV sets today are capable of at least 1920x1080 interlaced.
You are probably wondering "ok what is this progressive and interlaced mumbo-jumbo?" These are the types of scanning system the set uses. In the US there are 30 frames of a video image shown per second to the viewer. In "Interlaced" format, the screen shows every odd line at one scan of the screen and follows that up with the even lines in a second scan. With this format the screen shows one half of the frame every sixtieth of a second. For smaller screens this is less noticeable. But, as screens get larger, the problem with interlacing the image is a flicker type effect. This may be more noticeable to some people and less to others. Progressive scanning shows the entire image every sixtieth of a second. This provides a much smoother picture. However the progressive format use slightly more bandwidth and at higher resolutions is usually more expensive.
The current formats used in HDTV are:
* 720p - 1280x720 pixels progressive
* 1080i - 1920x1080 pixels interlaced (most common)
* 1080p - 1920x1080 pixels progressive (usually more expense but becoming very popular)
There are several types of HDTV on the market today. The main types are as follows: 1) CRT Picture Tube - a higher resolution version of your standard television set. 2) Rear Projection TVs - gives a high quality image at much larger screen sizes. 3) LCD - gives a very clear image but usually at a much higher cost especially as the screen size increases. 4) LCD Projection - this is similar to regular LCD but the image is projected instead of using one LCD panel for the entire size of the screen. 5) DLP Projection - the newest type which uses a special chip with tiny mirrors that is projected giving a very brilliant crisp image even at large screen sizes.
For a more detail description and the pros and cons of each type, please click on the type you are interested in from the menu bar on the left. You will also find user reviews and buying guides for each type and model.
DTV vs EDTV vs HDTV
If you are subscribed to cable tv or use a satellite service, then you probably already have digital television or DTV. The largest difference between DTV and a standard analog signal is that the signal is digitally encoded. This means there will be no "snow" or interference artifacts in the image. The problem is that the signal is usually converted to an analog format to be compatible with your existing tv sets. Although much better than an analog signal to begin with, you could still get some interference.
Your DVD player is a good example of pure DTV. You probably notice how clear a DVD plays compared to an analog VHS VCR. While normal DTV is much better than what we have saw 10 years ago, it is lacking significantly compared to HDTV.
Most of today's DVD players are capable of progressive scan at a 480p resolution which is called Extended Definition Television or EDTV. This gives you a step up from standard DTV format and at a wider screen format (16x9) capabilities. While this gives a better quality and theater like image, it still does not compare to HDTV. Be careful when shopping for a widescreen HDTV and not to mix it up with EDTV. It does not mean you should avoid EDTV, which is much less expensive than HDTV, but you do not want to confuse the two.
HDTV is a format of DTV but at much higher resolutions. Most standard DTV signals use the normal television resolution of about 500x525 pixels which is quite small compared to the 1920x1080 pixels of most HDTV sets. The larger resolution will show much more detail and sharpness in the picture. In fact it is very life like. While even standard DTV will show a nice and clear image of say a news caster. You can tell the news caster is wearing a nice black suit. But imagine not only seeing the color of the suit but the actually lining and thread in the suit just like if you were standing right in front of him. This is what HDTV will bring to you.
Screen Size or Aspect Ratio
All TV sets come in two 'Aspect Ratios.' Aspect Ratio refers to the ratio between the horizontal (width) measurement and the vertical (height) measurement of the screen. A normal television has an aspect ratio of 4:3 which means it is 4 units wide by 3 units high. Although HDTV can come in this ratio, especially with CRT types, most use the 16:9 aspect ratio which is 16 units wide by 9 units high. This gives you the widescreen viewing just like in a movie theater.
A typical TV broadcast uses an aspect ratio of 1.37:1 which is 1.37 times as wide as it is high. This converts well to a standard television set which is 1.33:1 or a 4:3 aspect ratio. However, most theater movies are 1.85:1 or 2.35:1. To convert this to the 4:3 aspect ratio of a normal television set the image must be panned and scanned. This means the image must be cropped down to the 4.3 size of the screen eliminating part of every frame of the video or letterbox it which means to show the full image, but only in the middle of the screen, causing black bars at the top and bottom.
Most HDTV screens have a much wider aspect ratio of 16:9 (1.85:1). This is how it can display such a high resolution. Widescreen movies will not be panned and scanned so you get the full picture as if you were watching it at the theater. And even if the picture is in a 2.35:1 ratio, it will convert much better than on a 4:3 standard television set.
This post first appeared on Update Gadget For Your Home Entertainment, please read the originial post: here
