A couple salespeople described these as “microdisplays.” The moniker seemed more than a bit outrageous given the large screen sizes, but the part of the TV that generates the actual picture is about the size of your thumbnail and is broken down into a grid of even smaller elements called pixels. An industrial-grade lightbulb illuminates the image and will eventually need to be replaced. Longevity varies, with bulbs lasting 2,000 to 4,000 hours and costing a few to several hundred dollars to replace. We had to decide what technology we wanted first, though––as there are a few advantages and drawbacks to each–– before looking into other features. Most of the salespeople I spoke to could hardly describe the differences, let alone how each technology worked. Fortunately, you don’t really need to know either, and can just look at the picture.

Liquid Crystal Display - A TV  that uses LCD technology is usually inexpensive and often has great color fidelity, but sometimes has a high black level, which means that dark portions of the picture will be slightly gray. The crystals in an LCD TV can also be more noticeable than other technologies.

LCD displays, for example, are the least expensive type of digital RPTV. The models I saw also seem to have more natural colors than other technologies, though none of the salespeople could explain why. The dots that make up the picture in an LCD TV are slightly more noticeable than with other technologies, which makes it look like you’re watching the image through a screen door. Black portions of the image also don’t get as dark as they do on DLP or CRT-based TVs, which makes shadows easier to see in bright rooms, but flattens or washes out the image in a dark room.

DLP technology, on the other hand, creates darker blacks than LCDs and has a similarly bright image, creating excellent contrast or depth to the image no matter what the room lighting. The DLP’s pixel structure is also more closely packed together than an LCD’s, rendering it nearly invisible. DLP TVs use color filter wheels to create the color in the image. This process can create rainbowlike trails of colors behind moving objects for a small percentage of viewers. It didn’t for me, but then color accuracy on less expensive DLP televisions didn’t seem as good to me as from LCD TVs. Some expensive DLPs, like RCA’s 7-inch deep model, looked outstanding.

Last but not least there’s LCoS. The salespeople were the least knowledgeable and most skeptical of LCoS technology, despite some of the great pictures I saw. My go-to guy, Carlos, explained that numerous manufacturers—including chip giant Intel—have tried and failed to make LCoS work economically, pulling products from the market as quickly as they introduce them. Others, such as Sony and JVC, have been more successful. LCoS is an advanced form of LCD that is similar in quality to DLP.

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.

Several salespeople seemed eager to sell us an integrated HDTV, pointing out that we’d need the built-in HD tuner to receive and decode the off-air HD signals that would come from my antenna. Integrated sets cost a couple hundred bucks more than what are called monitors—sets that have the resolution to display HD signals, but lack the internal tuner. Manufacturer terms for these sets range from “HD-upgradeable” to “HD-compatible” but they all mean the same thing. If you have cable or satellite, you probably already have a separate tuner and an HD monitor is fine.

Liquid Crystal on silicon - The third type of digital TV technology is LCoS (pronounced “el-koss”), and despite attempts by various manufacturers, is only currently available from Sony and JVC. Like a hybrid form of LCD and DLP, the technology combines the advantages of both, but can also be a bit more expensive.

The integrated tuner’s added cost (and resulting commission) may have sparked the salespeople’s enthusiasm, but the built-in hard drive, or digital video recorder that many of these TVs include sparked mine. The DVR can record TV shows like a VCR but has many other advantages, too, like constantly recording live TV so that you can press pause when the phone rings.

Many integrated sets are also digital cable ready. I could get a CableCard from the cable company, plug the card and the cable line into the TV, and be rid of my cable box altogether. A quick call to my cable company, however, suggested that all would not be so ducky. The digital-cable-ready TVs don’t use the cable company’s on-screen channel guide, can’t access video on demand, and don’t always have dual tuners. This seemed somewhat useless. By law, the cable company is required to provide cards when asked, but the customer service rep mentioned that some TVs have problems accepting an area’s given CableCard—a fact I confirmed with a few neighbors. The cable company’s external dual-tuner, HD-DVR cable box has none of the same drawbacks as CableCard, but does cost a bit more per month.

If the cable company offered more local HD channels, all would be good. But mine doesn’t and its HD-DVR cable box wouldn’t decode off-air signals, which meant I’d still have to get an integrated TV and change inputs for cable versus off-air channels. I could just wait until more local channels were available on cable, but I hate waiting. Frustrated, I cancelled my cable service and signed up for Dish Network’s satellite service, instead. Their PVR-942 receiver not only includes an HD-DVR, but decodes off-air signals, too. The savings on the HD-monitor would offset the cost of the receiver somewhat, but the system would be simpler and my monthly bill would be lower.

Connections   The only thing left to consider was the television’s back-panel connections. Carlos suggested purchasing a TV with more connections than I had components for. Since I route many signals through my audio/video receiver, we could get by with fewer inputs. He helped me map out a connection plan, which covered most of the basics.

While most new televisions have plenty of component inputs (called YPrPb—used on DVD players and many HD tuners), I wanted at least one component input that would accept standard- and high-definition signals, as my son’s Xbox will output both types of signals depending on the game he’s playing. I had to consider digital video inputs, too (DVI and HDMI), which aren’t available on my existing A/V receiver, and wanted as many of those as possible. Better satellite receivers (such as the Dish PVR-921), computer video cards, newer DVD players, and the promised Blu-ray or HD-DVD players—assuming either format becomes available—use these digital connectors. I could also use an RGB or VGA-type input for my computer. If you are going to get an integrated model, make sure it has FireWire, which can output the internal HDTV signal to an external HD-recorder (like said Blu-ray or HD-DVD recorder). Other sources would run through my receiver, so I only needed a couple composite and S-video connections. Your needs may vary. 

I haven’t yet decided which TV to purchase. It took a while to figure out what to look for, but visiting a handful of dealers and taking an average of what they said gave me a good idea of the factors that would ultimately be important. All I have to do is take a reasonable assessment of the lighting in my living space, know how far I will sit from the TV, consider how I’m going to get HDTV service, and keep track of the components that I will connect to the display.