Having picked out a few selections that fit our living room’s typical light levels, and numb from all the technical explanations, we changed the direction of our search to focus on some of the features found on current TVs. When I bought our last TV, the only thing I had to worry about was if there were enough inputs on back to accommodate our VCR and cable box. Now there are a few more things to consider.

Digital Light Processing - DLP technology, invented by Texas Instruments, uses nearly a million microscopic mirrors to create the image. These TVs have better black levels, better contrast, and less noticeable pixels than LCD. Color fidelity can be, but is not always as good as it is on LCD TVs.

Resolution (SD, ED, and HD) Fortunately, we didn’t have to worry about the resolution difference between what are known as standard-definition (SD), enhanced-definition (ED), or high-definition (HD) compatible TVs as nearly all digital RPTVs fall into the latter group.

There’s just no other choice. Some are theoretically more HD-capable than others, though. Most HD displays have a 720 line vertical resolution, which relates to the number of horizontal lines or rows of pixels—measured vertically—used to create the image, and this resolution corresponds to the same high-definition signal resolution broadcast by networks like ABC and Fox. But CBS, NBC, and many satellite and cable channels use a different high-definition signal called 1080i. When these signals are played back on a 720p display [and all processing issues aside—please see the 1080p feature on page 36], the TV only uses 720 of the 1080 pixels. Even when these signals lose a third of their vertical resolution, they still have enough left to be considered high definition and look great, but some new TVs are 1080p-capable and can play the full 1080 line signal. These sets are more expensive, though.

In most cases, I couldn’t tell the difference between the two. My ophthalmologist pointed out that the human eye could only resolve so much information. If you sit more than one and a half times the picture size (measured diagonally) away from the screen, your eye may not be able to see the difference between TVs with 720 and 1080 resolutions. Carlos effectively demonstrated a lack of image distortions and artifacts on a 1080p TV, but it was a subtle difference.

Integrated Televisions versus Monitors   The resolution advantage of any high-definition television is lost if you don’t actually feed the TV a high-definition signal. For this you need a rooftop antenna, digital cable or satellite signal, and even then, only certain channels are available in high definition. Carlos turned me onto antennaweb.org and titantv.com, websites that can help you determine what HD signals you can get. We have digital cable, but the cable company only offers a couple of HD channels. Fortunately, here in Springfield, Mass., there are a few local broadcasters that transmit HD signals over the air, as well. I decided to reconnect our home’s dormant and neglected rooftop antenna so that we could receive the local signals.