Since the early days of television, one of the principle challenges has been to deliver transmissions of high quality video with consistency. Throughout the world, several video standards, notably PAL, SECAM, and NTSC have attempted to achieve such quality. Since just after the Second World War, the United States has been committed to NTSC, named for the National Television System Committee that adopted it. This analog television system uses 525 lines of resolution and 30 frames per second but is constrained in no small part by the complexities and inconsistencies involved in transmitting audio and video over the air waves. Hence, its nickname among technicians: “Never The Same Color twice in a row.”
After more than a half century of use, NTSC transmissions will be replaced in the United States by a new standard, ATSC [Advanced Television Systems Committee] on February 19, 2009. After that date, full-power stations will broadcast digital signals only. For more information about the deadline and its possible impact, link to www.DTV.gov. As it turns out, 3,000 low-power stations will not be making the transition immediately owing to its costs. To see the new digital transmissions, owners of older analog television sets will need a decoder or set-top box to translate the new digital signals into an analog signal that the older TVs can understand.
Above all, don’t worry and don’t fall for unneeded upgrade schemes. Princeton’s Campus Television network will operate as normal. Even without a converter, you will still be able to receive some channels over the airwaves via the analog network. If you use a digital tuner from Comcast, FIOS, DishTV, etc, you will not have to take any action whatever. But if your analog TV is using basic cable without an external tuner, you will need to add one.
The encoding and transmission of images and audio in a digital bit format has many advantages. The delivery of audio and video will be much more consistent. Colors won’t fluctuate, recordings won’t vary from the original, and digital pictures will be free from the “ghosts” and “snow” that can affect analog transmissions. Moreover, the digital formats also facilitate a range of new commercial ventures. For example, you can record content or use a Tivo service to record for you. And digital providers offer free and for-pay on-Demand services that make available large libraries of movies and special features. You can watch them, pause your viewing and resume later, or even rewind to review a favorite scene.
At his April 30 Lunch ‘n Learn seminar, David Hopkins emphasized that hooking up to a digital service does not mean that all programming will be in high-definition. Services simply provide digital signals. To obtain high-definition programming, you will need to subscribe to a more-expensive tier of service. The preferred new wide-screen format is delivered in a 16:9 aspect ratio that emulates a movie-going experience.
Prices for High-definition televisions range from $499 (for 23” sets) to $70,000 (for sets that now reach 103”). Hopkins stressed that consumers ought to pay attention to each set’s contrast ratio, an assessment of its ability to display a full range of color. He recommended a minimum of 2000:1. All high definition models have some disadvantages, says Hopkins. Rear projection sets are relatively bulky and can be difficult to view well from the sides. To avoid costly maintenance, such sets should be regularly vacuumed. LCD’s are much thinner but have relatively slow refresh rates. Plasma displays provide a deeper black than LCD sets but will often experience problems with burn-in. Projectors generate large images but contain loud fans and have expensive bulbs that will need be replaced regularly.
If you are interested in wall-mounting your set, Hopkins recommended that you work with a professional, especially with larger models. When you decide to add a separate audio system, consider 5:1 Dolby Surround Sound.
And lest you think that Comcast, FIOS, and DishTV are the only games in town, Hopkins recommended that you take a look at online providers, notably Hulu, Joost, CNETTV, and tomgreen.com. Be prepared for a new addiction.
Posted by Lorene Lavora