Shopping for a New TV?
By Richard Meyer
Although you may not need to purchase a new TV to meet the broadcast requirements coming in February 2009 (see sidebar), changes and constant improvements in technology are occurring in TVs. The big question is “plasma or LCD?” Here is some information that may help you the next time you’re shopping for a new TV.
Plasma vs LCD
The term plasma refers to the small amount of plasma gas that is used in this technology. LCD stands for liquid crystal display, a similar technology as used in watches and calculators. If you’re thinking of purchasing a flat panel TV with 42-inch screen or larger, you will need to decide if plasma or LCD is a better choice.
• Plasma TVs perform better at wide viewing angles, top to bottom as well as side to side. If a panel is going to be mounted flat against a wall at a relatively high viewing angle, the plasma will look better.
• Screens smaller than 42-inch are typically LCD. LCD TVs seem to do better in brightly lit rooms. The LCD has a satin finish to the screen, where plasma is glossy.
• LCD TVs run a little cooler than plasma but both use about the same energy under normal operating conditions.
• Viewers who frequently watch sports or fast action programming usually prefer plasma TVs. The bright colors from a video game may be slightly better on plasma. However, the LCD technology is constantly improving in these areas.
• For faster action on an LCD, look for 120 hz refresh, rather than the standard 60 hz. Hz is an abbreviation for hertz, the new way of saying cycles. Household electricity is 60 hz of a.c. (alternating) current.
• For vivid color and deeper blacks, look for a higher contrast ratio (the difference in light intensity between the brightest whites and the darkest blacks a display can produce). In 2007, a good contrast ratio was 2,000 to 1. Now, a reasonably priced set can have 10,000 to 1 or higher.
• Panel life (how long a TV stays bright) is no longer an issue. Both plasma and LCD now are rated at 60,000 hours (20 years of normal viewing) before they reach half of their original brightness. Burn-in, of images or black bars on the top or sides, is no longer an issue or difference.
Both plasma and LCD TVs are available in a variety of resolutions (720p, 768p, 1080i or 1080p) that all qualify as HDTV (high definition digital television). Resolution is measured by the number of scan lines in each frame of a picture. The “i” stands for interlace, the “p” stands for progressive. If the lines of resolution are equal, p is considered better than i, there’s less flutter. 1080i vs. 720p, is in most opinions, an equal. Interlace brings all the positive lines down first, followed by all the negative lines. On progressive scan a negative line follows a positive line. A standard analog broadcast is 480 lines scanned interlace (480i). Some TV stations have chosen 720p for their signal others use 1080i.
The buzzword this year is 1080p, some times referred to as Full HD, because that is the highest resolution available. Currently the only 1080p content is in HD DVD and Blu-Ray disc formats, not from cable or broadcasts. The main benefit of 1080p sets is that you can get a larger screen before the individual pixels become visible (or you can sit closer).
And coming full circle, let’s look at screen size and aspect ratio. Previous TVs all used an aspect ratio of 4:3 (almost square in size). All, but the smallest flat panels, are now 16:9 (rectangular). The same standard to measure the screen is still used. Screen size is measured diagonally. For this reason, a 20-inch 4:3 has about the same picture height as a new 26-inch 16:9; an old 27-inch TV would be replaced by at least a 32-inch wide screen; an old 36-inch, a new 42-inch.
The reason to go bigger is that even though the screen is wide, the production or broadcast won’t always be. It’s like putting a round peg in a square hole, not all the space is covered. Most wide screen TVs will let you adjust the size or shape of the picture; this will either distort or cut off part. Sorry, but this will be a slow transition. Old M*A*S*H reruns will still be around awhile.
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