Q: \u00a0 \u00a0 I am hearing that a DirecTV HDTV signal is far superior to a HDTV signal from my cable company. \u00a0Is this true? My cable company is now offering HDTV through its digital service but I understand that this is sometimes a very soft signal. Garbage in and garbage out really has never reached such levels because I know that a bad signal on a great HDTV is only magnified like never before. Can you help, what do you know about this?<\/p>\n
-Mike Freer, Columbus, Ohio<\/p>\n
A: \u00a0 The quality of the HDTV signal transmitted over cable systems is wholly dependent on the particular cable company. \u00a0 The quality of the signal will vary depending on the capacity of their system and their philosophy when it comes to image quality and signal transmission. \u00a0<\/p>\n
Cable companies have capacity limitations over their cable systems, and an HDTV signal transmitted at full quality takes up a lot of available space. \u00a0 There have been reports that some cable companies offering “HDTV” service are not transmitting HDTV channels at full quality in order to conserve this space for additional pay-per-view offerings, video-on-demand and other similar channels and services.<\/p>\n
Digital television signals are composed of millions of digital bits transmitted every second. \u00a0 The more bits, the better the picture. \u00a0 To be considered true HDTV, the signal must be at least 19.4 million bits per second. \u00a0 \u00a0 I recently spoke with a technician installing new capabilities for one of the country’s largest cable providers. \u00a0 I asked him what bitrate they are using for HDTV, and he told me it was 10 million bits per second. \u00a0 While such a picture may look good compared to a regular digital channel, it is still well below what a full-quality HDTV signal should be.<\/p>\n
A few months ago I received a question similar to yours regarding HDTV via cable. \u00a0 I contacted three cable companies and asked the bitrate being used for their “HDTV”. \u00a0 All three companies said they would get back to me. \u00a0 None of them ever did.<\/p>\n
In terms of personal experience, I recently visited a friend who is getting HDTV via cable. \u00a0 She has a Mitsubishi HDTV similar to the one I own. \u00a0 Watching the PBS HDTV demo channel, it did not have nearly the clarity, vibrancy, or visual impact I experience with my Mitsubishi HDTV receiving the same channel via an antenna. \u00a0 While she thought her picture was very good, I imagine she will be disappointed with it when she sees the same channel on my television running at full quality.<\/p>\n
Again, cable companies differ. \u00a0 If image quality is of prime concern to you, I would recommend you stick with HDTV via satellite or via an antenna over-the-air as it is a safe bet. \u00a0 If would like to give HDTV via cable a try, call and ask a technician what bitrate they are using for HDTV transmissions. \u00a0 If their HDTV is being broadcast at 19 million bits per second (Mb\/s) or greater, you should have picture quality that rivals satellite and over-the-air HDTV transmissions.<\/p>\n
Q: \u00a0 \u00a0 My Toshiba TV has a setting called “Theater” in the picture controls. \u00a0 I have tried it and it just seems to make the picture darker. \u00a0 What is it there for?<\/p>\n
-Katherine Shaw, Cranberry, PA<\/p>\n
A: \u00a0 On most televisions, including your Toshiba, the “Theater” setting is designed to be used it total darkness, just like the movie theater experience. \u00a0 When you activate this setting, it makes subtle adjustments to the picture that imitates the depth and look of a movie screen showing projected film. Try it in a totally dark room next time with your favorite DVD.<\/p>\n