- Analog vs. Digital
- Interlaced vs. Progressive
- Widescreen vs. Standard Aspect Ratio
- Standard Definition vs. High Definition
- The Cost Factor: How Much Do I Spend?
Analog vs. Digital - How do digital television (DTV) and high definition television (HDTV) technology differ from the traditional analog TV we all grew up with? The standard analog, or NTSC, (National Television Standards Committee) video signal is transmited as an analog wave form. One major problem with analog signals is that as the signal passes between the transmitter and your TV set many things can impede or interfere with the wave form, distorting the picture you see. Mountainous terrain, radio interference, and even atmospheric conditions all are obstacles that can disrupt an analog signal. Also, the strength of the analog signal is critical; a weak signal can cause "snowy" or distorted pictures. Rather than deal with wave forms, digital TV signals are made up of coded binary instructions - the same "ones and zeros" that make your computer, CD player and DVD player work - which are transmitted directly to your digital tuner (COX digital cable box, satellite decoder, etc.) which deciphers the transmitted "ones and zeros" back into a television picture. Unlike analog broadcasts, your digital tuner isn't concerned with signal strength, or what conditions exist between you and the transmitter. As long as the digital signal gets to the receiver, it can be read and will create a perfect picture.
Interlaced vs. Progressive - Television pictures are comprised of scan lines. Standard definition broadcasts consist of 480 viewable interlaced scan lines measured from top of the picture to the bottom. Interlaced means that only the odd or even numbered lines of the picture are being shown at any given time. The switch between the odd and even lines occurs 60 times per second. (60 Hz) Many digital formats utilize a progressive scan which puts all 480 lines of the picture up on the screen at all times; basically doubling the pictures resolution. This higher resolution translates into a sharper picture with more depth and color detail than a standard interlaced picture.
Widescreen vs. Standard Aspect Ratio - The new high definition (HD) format uses a different aspect ratio to show it's pictures. When you sit down to watch a TV broadcast today, the majority of sets on the market are what's called "4 x 3". This term describes the relationship between the pictures horizontal measurment and it's vertical measurment. A "4 x 3" set is almost square in shape and has been the standard form for TVs for decades. When you go out to the movies you'll notice that the screen in the theater is not square shaped at all. Theater screens are rectangular in shape; wider than they are tall. This aspect ratio is called "16 x 9" or "widescreen". The majority of high definition broadcasts and DVD movies are recorded in this widescreen format to allow for a more theater-like experience in your home. Almost all of the television sets that we carry at Jerry's are widescreen. The reason being that once the switch to high definition (HD) has been accomplished, the older style "4 x 3" sets will be obsolete. We've already geared up for the future so you don't have to worry about purchasing nearly extinct equipment!
Standard Definition vs. High Definition - There are some common misconceptions regarding the "digital switch" that US broadcasters are presently involved in. One of the most common we hear is that "all digital TV is high-definition". This is not true. Unfortunately, it is easy to confuse the two but there are some important differences between digital and high definition that we will now discuss. As we discussed earlier, standard television pictures are comprised of only 480 scan lines. High definition TV is available in a few different formats, the most common of which is 1080i. 1080i digital signals are interlaced, but rather than containing the standard 480 scan lines found in our analog broadcasts, the 1080i format is comprised of 1080 total scan lines. This increase in vertical resolution dramatically improves picture quality and color depth. In addition to the increased vertical resolution, 1080i also provides up to 5 times the amount of horizontal resolution, creating images so bright and vivid it's just like being there. In fact, high definition is so clear we can't even truly demonstrate it on your computer monitor! You'll have to come into the store and take a look for yourself!
The Cost Factor: How Much Do I Spend? - How much do you have? Seriously, though, budget and intended use will determine the direction you take in what technology you choose. Those with the strictest budgets will want to break into HDTV via LCD rear-projection or CRT rear projection. At this price range ($1500 - $2000) CRT rear projection will most likely be the better performer, but at the cost of weight and power consumption. If you are desperate for flat panel, its going to be a question of size. LCDs cost more than Plasma TVs at equal sizes. The reason for this is production yields and undersupply. There is currently a condition of undersupply for many sizes of LCD displays due to the number of manufacturing plants available and the current configuration of those plants. Couple this with lower yields on larger display sizes due to burned out pixels and quality control, and you have a demand situation which forces LCD prices up for larger displays. A fair estimate would be that above 30 an LCD TV costs at least 30-40% more than a comparable Plasma display. If you want the benefits of LCD you will have to pay for it and we thought Plasma was expensive! If you are made of money and want the biggest flat panel around, Samsung and LG have been battling it out for years, but Samsung has won largest in both Plasma and LCD this year. They unveiled a 57 LCD TV and an 80 Plasma screen, both are top in their category and are priced at well, more than you want to know.