TV Buying Guide

On Feb 17, 2009 all full-power TV broadcasting stations will stop broadcasting on analog airwaves and the only broadcast will be in digital. People having "analog" TVs and relying on airwaves (through antenna) won't be able to watch their favorite channels unless they get a digital convertor box. An alternative is to buy a new "digital" TV. My wife an I had been thinking of buying a big flat-screen TV from around a year, and this announcement gave us good motivation to go out and look for a new TV. The selection of right TV turned out to be a bigger problem than it appeared. With a number of TV technologies each having its own pros and cons, coupled with the myriad brands in the market, we had to devote some time to figure out which model will best meet our requirements. During this process, we learned a number of new technical terms and details which we hadn't paid much attention to earlier. Given below are a number of key parameters one should consider while buying.

1. TV Technology : LCD, Plasma and DLP are three of the TV technologies available in the market.
• DLP (Digital Light Processing) TV is a method of dispalying video using rear projection light. It is basically a video projector in a box. DLP screens are larger and cheaper than a LCD or Plasma for the similar size. However the clarity is not as good as LCD or Plasma TVs and one has to replace the bulbs after a few years.
• Plasma: In Plasma TVs, little bits of plasma are excited, which then strike specific pixels at the front of the TV, causing the pixel to turn a specific color. Plasma TVs are very good for dynamic images. However they can have burn-in issues if a static image is displayed on the screen for a long time.
• LCD (Liquid Crystal Display) : In LCD TVs a liquid controls each pixel and can change the pixel's state to different colorsPlasmas and LCD TVs both have their own pros and cons and frankly its up to the individual which kind of TV he prefers
2. TV Size : The link here gives a table showing the normal viewing distance and the recommended TV size for such a distance.
3. Resolution (1080p vs 720p) : ‘P’ stands for progressive scan or non-interlaced. Progressive scan conveys all of the lines of resolution sequentially in a single pass, which makes for a smoother, cleaner image. Interlaced on the other hand will convey every other row in a single pass. The number 720 stands for 720 lines of vertical display resolution and the number 1080 stands for 1080 lines of vertical display resolution. 1080P (more pixels and hence more expensive) will provide more clarity and will allow you to get the most out of the next generation games and Blu-Ray movies.
4. Contrast Ratio : Contrast Ratio, is the ratio of light intensities of brightest and darkest colors of the display. The more the contrast ratio, the better the clarity. Static CR, is the measure of ratio between brightest and darkest colors appearing on the screen concurrently. On the other hand, the second type of contrast ratio, known as dynamic CR, is measured as ratio between brightest and darkest colors appearing on the display at different times.
5. Response Time : Response time is the amount of time it takes for one pixel to go from active (black) to inactive (white) and back to active (black) again. Response time is measured in milliseconds with the lower number being faster or better. Poor response time will be result in a smear or blur being seen on fast moving objects.
6. Refresh Rate (60Hz vs 120Hz) : A 60Hz display refreshes it's image 60 times per second and a 120Hz display doubles that. The main goal of 120Hz displays is to eliminate judder when displaying film for a source of 24fps. With 60 HZ displays such material is shown for different length of time: every odd frame - twice, every even frame - 3 times (12*2+12*3=60). This is called 3-2 pulldown. A 120HZ display shows every frame 5 times (5*24=120), hence, no judder. There will be no difference in presenting 60Hz footage (what sports mostly uses) between those two displays.
7. Other Features : These include the number of ports available on the TV (HDMI, S-video, Component), sound system (this is less relevant as most of the time people end up buying a home theatre system along with the tv), color etc. It is good to go to a store and look at the model to get a feel of how it will fit into your lifestyle.

If one picks a system that gives all the best features and the highest clarity, that will cost a lot of money. Therefore, one should look at what basic minimum features the TV should have without hurting the viewing experience or his pocket to a great extent. Here is a list of things I found out over the internet.

- Resolution : At this time the TV boradcast by HD stations is in 720p. Even if you buy a 1080p tv, you wont get any better picture than on a 720p TV. However if you watch Blu-ray movies and play latest video games only then can you get the best out of a 1080p TV. It has not been decided yet when will TV broadcast begin in 1080p. 720p tvs are approx $300-$400 cheaper than 1080p TVs. Therefore if you are buying a TV just for watching broadcast programs you can even look at 720p TVs. My personal advise, however, is to pick a 1080p TV keeping in mind that future broadcasting will be in 1080p.

- Contrast Ratio : Experts advise people to pick a TV with a CR of at least 10,000:1. There will be little to no visible difference if you go above 20,000:1 ( This is considering a normal TV viewer, not one who is really fussy about extremely high clarity).

- Refresh Rate : 60Hz refresh rates are good enough and you wont feel any difference compared to a 120Hz one unless you are into high speed gaming.

- Select a reliable brand (Sony’s are generally expensive than others because of the name. Samsung and Sharp are also good brands).

- Read the reviews of the model you decide to buy. CNET is a good source of TV reviews. Here is the link http://reviews.cnet.com/televisions/

Once you decide on a particular model, you can do a comparison shopping. Pricegrabber.com and shopzilla are two good sites. Most stores will give you a 30 day price guarantee. You can enroll at priceprotectr.com to see if the price of your product falls within the 30 days after your purchase.