HDTV Made EZ
By now I am sure you have been hearing the entire buzz about this HDTV stuff. You are probably wondering, what’s the big deal.
HDTV stands for High Definition Television and has ushered in a whole new way of watching TV. But what is HDTV?
HDTV is a technology and not a television. Essentially HDTV is the use of a digital signal versus an analog signal. A digital signal allows you to view a television show that is so clear, it looks as though you are looking through a window.
Desperate Housewives looks better, CSI looks better, Law and Order, looks better and all sporting events look better.
There are two kinds of television sets:
Standard Definition TV (STDTV), let's call it Normal
High Definition TV (A.K.A. HDTV), or High-Def-TV
The differences between the two are the number of pixels each contains. A pixel is short for “picture element” or to make it even easier to understand a pixel is those dots you see on the TV when you look closely.
The picture on a TV set is formed by dots of light (call pixels, remember), on a SDTV there are only 540 across and down displaying the picture on your TV set. On a HDTV, there are more than 1920 across and 1080 down.
The more dots (pixels) the better the picture - All of those extra dots (or pixels) are the main reason the picture looks so much better. That better image is call resolution.
Screen Resolution
Resolution refers to the apparent quality or sharpness of a video image, signal or display.
It's usually measured in terms of the density of lines and dots that make up the display, and often referred to as "line resolution", which is where you get the terms 480p, 720p, or 1080p, this is short for "pixel count".
HDTV’s can show a clearer picture than standard TV’s, especially up close. They show pictures in greater detail.
HDTV has the following resolutions:
- 480p - Good
- 720p - Better
- 1080p – Best (today’s standard)
Types of HDTV’s
High Definition TV’s come in three styles:
1. LCD Flat Panel
2. Plasma
3. Rear Projection/Micro Display
LCD (Liquid Crystal Display) Flat Panel - TV’s are slim light-weight panels that respond to electronic signals to display light and color on a screen. They are basically large flat screen computer monitors. LCD technology is based on the properties of polarized light.
Two thin, polarized panels sandwich a thin liquid-crystal gel that is divided into individual pixels. Also, image brightness can be very high and color performance can be good, especially if they are placed in rooms that are brightly lit, whether natural or artificial light. Similar to plasma TV’s, LCD TV’s tend to show the best pictures at smaller sizes, and require much less power to operate than plasma screens.
Plasma TV’s Are similar to LCD TV’s; they use an image display device technology using hundreds-of-thousands of miniature, embedded cells. Each one of these corresponds to one pixel, (picture element) and has three sub-cells. The three sub-cells are filled with a plasma gas which will 'glow' red, blue or green (depending on the phosphor coating) when charged electrically.
Light from the three "RGB" sub-cells combines to form a one colored pixel on the screen. Some early plasma devices were susceptible to "burn-in", an unwanted retention of an image that may be permanently scarred onto the screen. This can still occur in newer models but not as much.
Plasma screens are generally less expensive and do a better job of showing darker colors (especially Blacks) than LCD and rear projection TV’s. They show a much better picture in dimly lit rooms and are better at showing motion and action images such as sporting events.
Another major advantage: Plasma TVs have a virtually unlimited viewing angle, so the picture quality doesn't decline when you watch the screen from the sides as it does with most LCD sets and rear-projection TVs.
Projection TV’s – (also called MicroDisplays) generally give you the best for less, meaning they can be bought for less than LCD and Plasma TV’s. They are available in two basic configurations - front and rear projection with rear projection being the new standard these days.
Front projection TVs are generally in two parts - the screen and the projection device itself, which are positioned some distance apart. Many front projectors are 'portable' in use and nature, while fixed installed projectors are common in boardrooms and home theatre environments.
Rear projection TVs are usually a single unit, with built-in screen, connections, electronics and processing gear all in one box.
Projection TV’s are sold in basically three (3) display technologies:
- Liquid-Crystal Display (LCD)
- Digital-Light Processing (DLP)
- Liquid Crystal on Silicon (LCoS)
* The display technology means how the television creates images on screens.
Note: With most DLP sets, some people are bothered by what is called the "rainbow effect".
This is a flash of color some viewers see when moving their eyes across the edges of bright objects on a dark background.