Compressed signal affects image quality

Q I have a new flat-panel TV with a cable hookup and an antenna. I have noticed that sometimes the picture from the antenna looks noticeably better than the picture from cable on the same local channels. Is there a cause, and can it be fixed?

TIM WALLIN, SPRING PARK

A Your cable company might be compressing the signal too much.

The best image quality from HDTV network broadcasts are obtained with an over-the-air antenna. That way, you get the signal directly from the station in its purest form. The cable company and satellite companies receive the same signal and compress it so they can fit more channels on the limited bandwidth of their cable line or satellite. This can take a toll on image quality. Sometimes it is not noticeable; other times it is obvious.

The differences will vary based on the channel, the cable company and the region of the country. The satellite providers tend to do a good job with HD broadcasts, and the quality is identical nationwide. Some providers using 100 percent fiber optics, such as Verizon FIOS, do not compress their HD channels. They have virtually unlimited bandwidth, so they just transmit it as they receive it.

Q In an earlier column, you mentioned a Blu-ray/VHS combo player, the Panasonic DMP-BD70V. Have you tested it yet? I have more than 1,500 VHS movies and would like to know what you think of its ability to up-convert to 1080p. I am excited about the possibilities.

DICK DVORAK, MENDOTA HEIGHTS

A Many readers have asked me about the DMP-BD70V and its VHS up-converting performance. It does up-convert VHS to 1080p, but VHS tape is low resolution (about 240i), and you can't create detail where none existed. The DMP-BD70V's HDMI connection does produce an image that looks cleaner and more solid than an analog connection, although the colors and edge sharpness look exaggerated at times. It won't fool you that you are watching anything but VHS tape, though.

The big benefit of the upconversion is that you need only one HDMI connection to play VHS and Blu-ray discs, instead of the usual rat's nest of cables and connections.

Using the DMP-BD70V with a few of my remaining VHS tapes quickly demonstrated to me what a boon this player will be to people with VHS libraries. There's no changing of TV inputs to use your video player, image quality is slightly enhanced and there is only one connection.

The DMP-BD70V is absolutely great at what it does and provides an easy and seamless way to view your VHS tapes on your HDTV while adding Blu-ray for the ultimate in picture and sound quality. It is one of the best Blu-ray players you can buy, and DVD up-scaling is excellent as well.

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