Sunday, December 03, 2006

Two Useful HDTV Primers

If you're looking to buy your first HDTV for Christmas 2006, you may find you're overwhelmed. You're asked to choose among flat panels, direct-view picture tubes, rear projectors, and front projectors. Resolutions include 720p, 1080i, and 1080p. Imaging technologies at your beck and call include:

  • LCD (liquid crystal display)
  • PDP (plasma display panel), or just "plasma"
  • DLP (digital light processing)
  • LCoS (liquid crystal on silicon)
  • SXRD (Sony's "Silicon X-tal Reflective Display" take on LCoS)
  • D-ILA (JVC's "Digital Direct Drive Image Light Amplifier" LCoS version)
  • ... and the old-fashioned "picture tube," or CRT (cathode-ray tube).

What to buy? How to decide? How to figure it all out?

You can begin by checking out this HDTV Theater Feature at The guide's first section, "HDTV Benefits," tells you stuff you probably already know, such as how much wider the HDTV screen is — a 16:9 aspect ratio, to SDTV's 4:3 — and how much better multichannel surround sound is than stereo. And yes, you can get 4.5 times the number of pixels of standard-def TV — up to 2 million of them — but what's a pixel? Click on the word "pixels" and see!

The real meat-and-potatoes of the tutorial begins with the "Purchase Guide." Here the major types of HDTVs are described: traditional direct-view CRTs; flat panel LCDs and plasmas; and rear projectors using CRT, DLP, LCD, and LCoS technologies. (Front projectors aren't covered.) Notice that LCD technology appears in both flat panels and rear projectors.

The guide's "HD Setup" section is worth its weight in gold. Just click on "Basic Setup" or "Advanced Setup" and you'll see an easy-to-use interactive guide to all the confusing connections on the backs of HDTVs and other gear in your system. You can skip the "Get Discovery HD Theater" section unless you want to find out how to receive that high-def channel. The "Glossary/FAQ" section will get you started talking the talk if not walking the walk in HDTV land.

Another fine primer comes in the form of a pair of articles from the technology writer of The Baltimore Sun, Mike Himowitz.

The first, "Plasma? LCD? What to look for in HDTV," makes the point that "we've reached the point of diminishing returns on procrastination." Wal-Mart is supposed to be slashing HDTV prices this holiday season, with other vendors following suit. Why wait to buy?

Another key point: "HD manufacturers give you 11 percent less TV than you got for the same diagonal measurement in the old days." The "wider" 16:9 picture is, in a way, a squashed picture. To get the same screen area as with an SDTV you have to size up. So you may need a pricey new TV cabinet or stand.

That brings up an important point. Where are you going to put your DVD player, cable box, A/V receiver, etc., etc., etc.? With a conventional set, these pieces of gear often found their way to space above or to one side of the TV. No longer. The new sets usually don't have tops to set things on, and they intrude into the side space so much that you can kiss that goodbye. So, even if you wall-mount your new HDTV, you'll need a stand with plenty of shelf space under the TV.

Himowitz advises, and I concur, that CRT-based HDTVs no longer make sense. They're too deep, too heavy, and take up too much of the space beneath their screens. The best flat panels now provide just as good an image, cost less, and use less space. In fact, according to the December 2006 issue of The Perfect Vision, Sony will cease production of direct-view CRT HDTVs and CRT-based rear projectors.

Between the two major flat panel types, LCDs and plasmas, Himowitz advises to favor plasmas in larger sizes (over 40") and LCDs in smaller ones. But I'd say the gap has narrowed in the crucial size range of 40-42" to the point where you should let your eyes and pocketbook be the final judge.

Plasma pluses: really bright pictures, excellent colors, fairly deep blacks. Plasma minuses: they're heavy, hot, electricity hogs with a potential for burn-in of static images; 1080p models are as yet few and pricey. (Manufacturers now say they've licked the burn-in tendency.)

LCD pluses: 1080p resolution available for moderate prices; they reflect room lights less than plasmas; they're light in weight; no burn-in. LCD minuses: moving images can blur due to response-time lags; narrower viewing angles; blacks can be less deep than on plasmas. (Note that the very latest LCD panels pretty much conquer all these minuses.)

Himowitz makes it sound like rear projectors (as opposed to flat-panel HDTVs) are as much for techies as front projectors, but it just ain't so. Models of the LCD, DLP, LCoS, and SXRD varieties, the so-called "microdisplays" with magnifying optics inside, are no harder to set up and use than flat panels — though you ought to avoid the now-passé CRT projectors which require "convergence" adjustments — and they give you the most bang for the buck in screen sizes over 50". The downside: they do need an expensive new bulb every few years, off-angle viewing may be problematic, DLP sets make some people see tri-colored rainbows ... and they can't be mounted on a wall.

The second Himowitz piece, "HDTV specs matter, but what you see counts most," deals first with that confusing HDTV nomenclature. I'd say it's the best quick intro yet to terms like 720p, 1080i, and 1080p.

I disagree slightly with Mr. H's description of 1080p as "overkill," though. True, at present the only way to input 1080p to an HDTV is with a Blu-ray disc player, but it won't be long until HD DVD players and home computers can feed 1080p into HDTVs as well.

Also true, you need to be sitting fairly close to a reasonably large HDTV to see the difference between 1080i and 1080p. If your TV is of modest size compared with your viewing distance, your eyes will blur away much of the extra definition.

I'd still say that if you ever envision having a 1080p source such as Blu-ray, you ought to consider investing in a 1080p TV very, very seriously.

Then again, according to the December '06 issue of Consumer Reports, "DisplaySearch predicts that the average price of a 50-inch 1080p plasma TV will drop from about $5,400 this December to $3,100 by late next year." So if the words "plasma" and "1080p" are at the top of your HDTV shopping list, waiting another year may make sense after all.

As for 720p. Mr. Himowitz is right in calling it "entry level" HDTV these days. It has only 720 lines or rows of pixels, not 1,080 — though it wholly avoids the "i" vs. "p" debate; it's always "p."

Here's where things get truly confusing. I've talked of 720p, 1080i, and 1080p as if you understood those terms. I realize some explanations are due. I'll give them in another post, 1080p, 1080i, and 720p.

I would echo Mr. H. in advising you to find a store where you can view an HDTV in dim surroundings, from your actual anticipated seating distance. In my area, Tweeter is usually best for this. Circuit City and Best Buy too often crowd you in toward their TVs on display and/or use overbright fluorescent lighting.

Bring along a favorite DVD (ideally, one with a lot of dark scenes and bright scenes with a lot of action) and ask to view it with a remote control for the HDTV in your hand. You need to know:

  • How black do the blackest areas of the image get with BRIGHTNESS set suitably low?
  • How much "shadow detail" is there with BRIGHTNESS set that low?
  • How high can you set CONTRAST without "crushing" bright highlights on the screen?
  • Do colors look pleasing and natural?
  • Do faces look sunburned or flushed unless you set COLOR too low?
  • Do you see "false contours" in supposedly smoothly graded picture areas?
  • Do you see jagged edges on objects in moving images?

Another tip: bring along a black & white DVD! The picture should look a netural gray. If it doesn't, the TV may need a costly "grayscale calibration" to perform its best in your home.

The Himowitz article goes on to describe the various connections you may need to make to use your HDTV. To what he says I would add that you definitely ought to favor High-Definition Multimedia Interface (HDMI) connections over all others. He doesn't mention it, but HDMI carries audio as well as video signals, so if your source device outputs HDMI, one cable from it to the HDTV can do it all.

Digital Video Interface (DVI) inputs are the equal of HDMI, video-wise, but they're so two-years-ago. Don't put much stock in them today; their connectors are big and clumsy, and they don't carry audio. If you have a source device that outputs DVI but not HDMI, you can get a DVI-to-HDMI cable or converter for it ... but you'll need to route audio separately.

Of course, your HDTV ought to have enough HDMI ports to handle all your inputs. If it doesn't, you can get an A/V receiver that accepts multiple HDMI inputs and sends just the selected input signal to the TV, again on HDMI. Or you can buy a special HDMI switcher, but that's geeky to the max. Or you can fall back on routing high-def video from the source device to the TV via analog component-video wires, alias YPbPr.

In the latter scenario, or if you're forced to use DVI, audio is carried on its own wire(s). Himowitz is dead wrong to say that using optical and coaxial audio connections are for "tweaks" and buffs. They're the best way (short of HDMI) to route multichannel Dolby Digital or DTS surround sound to an A/V receiver or a home-theater-in-a-box.

Types of connections to be avoided, if possible, include:

  • S-video or composite video connections (use HDMI/DVI or component video)
  • 75-ohm coaxial RF connections, except from an antenna or cable wire
  • Stereo analog audio via right-left RCA audio ports (they're non-multichannel)

Finally, it's good advice to consider getting your HDTV and whatever gear you buy with it professionally installed. It ain't cheap, but it can require skill, expertise, and tools you probably don't have ... and heavy lifting you may not be prepared for.

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