If you're buying your first HDTV or an upgrade from a starter set, your new television may deliver a better picture than the one you're used to. But picking the right HDTV can be confusing, especially when your favorite blue-shirted salesperson may be steering you in a certain direction in hopes of a bigger commission. Or maybe the rep is just misinformed. Whatever the reasons, the environment has encouraged a cavalcade of claims about HDTVs--some of which were true for first-generation sets but have little relevance to today's buyers, some of remain valid, and some of which were never true.
I'll highlight some of the most prominent assertions made on the showroom floors of big-box retailers and explain the realities, along with tips and details for buying an HDTV, selecting the best content, hooking up the set at home, and more.
Claim: "HD" signifies a specific standard of quality.
Though "HD" does stand for "high definition," HDTVs come in several resolutions; and in any event, a set's resolution doesn't completely determine the exact image quality you'll see on your screen. For one thing, screen sizes vary. Other factors affecting the picture include the transmission--over the air, via cable, by satellite, or from the Internet--and the original source material.
These variables help explain why you can get high-def content from Amazon, Hulu, iTunes, Netflix streaming, a Blu-ray disc, and other sources, and yet encounter wildly different picture quality.
The basis for the real broadcast signal standards is ATSC (Advanced Television Systems Committee), and even that has many options.
If you have an HDTV and a digital tuner, ATSC governs your over-the-air signal. ATSC content may be in either standard-definition (in either 4:3 or 16:9 aspect ratio) or high-definition (16:9 aspect ratio) format, with the resolution varying accordingly. A standard-def transmission consists of 4:3 images transmitted at a resolution of 640 by 480 pixels.
The most familiar of the HD resolutions are 720p (consisting of a 1280-by-720-pixel frame) and 1080i (composed of 1920-by-1080-pixel images). The "p" stands for "progressive scan," meaning that the set creates the image by continuously redrawing the frame, line by line. The "i" stands for "interlaced," meaning that halves of the full frame are shown 60 times per second, but your eyes combine them into a full-frame image reproducing itself at a rate of 30 frames per second. At the same resolution, a progressive-format image looks better than an interlaced image.
Over-the-air broadcast standards top out at 720p and 1080i, but you can obtain the full 1920-by-1080-pixel frame in 1080p from Blu-ray discs, certain Xbox 360 models, and the PlayStation 3 units.
Compression and bit rate are other factors in picture quality. A Blu-ray disc should look better than a cable TV feed of the same content at the same resolution, since the disc has more bandwidth than the cable broadcast.
When choosing for picture quality, remember: 1080p is at the top, 720p and 1080i look similar, and anything below them won't be as good. Keep those terms in mind because they represent official standards, not marketing terms.
Claim: If you don't buy a 1080p HDTV, you're wasting your money.
In all likelihood, you want a 1080p HDTV--and you should be sure to get that resolution if your set has a diagonal screen size of 32 inches or greater, since you'll be able to see the additional resolution on a big-screen from across the room. Furthermore, there's no reason to avoid a 1080p HDTV if it doesn't cost substantially more than sets with alternative resolutions, given that 1080p is becoming ubiquitous. If the difference is within $100, I recommend going for a 1080p set if your budget can handle it.
But having said all that, I should warn you that you probably won't see any improvement in picture quality from 1080p versus 720p on a smaller HDTV. And you may not even have any 1080p sources to exploit: Over-the-air broadcasts and most cable feeds top out at 1080i.
If you're getting a big set or if you're connecting 1080p sources such as a Blu-ray player, a Microsoft Xbox 360, or a Sony PlayStation 3, a 1080p set is your best bet. But in many other situations, a 720p set will perform just as well for all practical purposes.