HD Ignorance Is Not Bliss! What Are Ten Things I Should Know About HDTV?

I have written many HDTV posts but have failed to provide an overview of oft misunderstood terms and high-definition subjects. In order to help shed light on these concepts, here are ten things that everyone should know about HDTV:

1. There are three major benefits that the HDTV format brings. Besides a lighter wallet and a slight headache, your HDTV setup should give you these main features: First, you’ll experience high resolution that provides great picture detail. The screen and content will have at least 720 lines of resolution. This is superior to standard or enhanced definition (DVD quality), which only has 480 lines of resolution. Second, you’ll have a widescreen format similar to a theater experience. HDTV content is presented in a 16:9 aspect ratio. This is wider than your older, boxier televisions. Lastly, HDTV uses 5.1 surround sound output. The sound content will be divided among five speakers plus a sub-woofer. These speakers include the left, center, and right channel as well as two addtional speakers at the back of the room.
   
   
2. Not all flat panels are HDTVs and not all HDTVs are flat panels. If you're a little confused by that statement, keep in mind that two wrongs don't make a right, but three lefts do. Flat panel televisions are those ultra-thin televisions that are typically no thicker than four inches. The plasma and LCD technologies currently dominate the flat panel market. While most flat panels are high definition, there are still some available as an inferior enhanced definition television (EDTV). Additionally, there are many HDTVs that are not flat panels. Microdisplays are not as thin as flat panels but at 10” to 18” in depth, they are much shallower than the old picture tubes. These microdisplays include DLPs, LCD Projections, and LCoS televisions. For more information on these HDTV types, read High Def Alphabet Soup.
   
   
3. Not all features are created equal, so be careful when comparing. Michael Jordan and I both have vertical leaps of 42 (inches for Jordan and centimenters for me). That comparison is similar to ones made on HDTVs. First, not all HD is the same. There are three popular high definition resolutions, all improvements over the 480-line enhanced definition resolution that DVDs provide. The 720p resolution is a progressive scan that renews all of its 720 lines each refresh. The 1080i resolution, similar in quality to 720p, uses an older interlaced scan that refreshes only half of its 1080 lines at a time. The 1080p resolution (also called Full HD) has a superior 1080-line progressive scan resolution that delivers more than twice the number of pixels as 720p. Due to its enhanced resolution, 1080p Full HD commands a premium price tag in the retail marketplace. Additionally, be careful when reading manufacturer specifications on contrast ratios. A dynamic contrast ratio looks at the brightest vs. darkest points over time, but the static contrast ratio evaluates this difference at a snapshot in time. Although manufacturers may not explicitly state which ratio is being referenced, very high dynamic contrast ratios are easier to achieve than static ones. An outstanding static contrast ratio is 1,500:1, while it is not unusual to see a dynamic contrast ratio over 10,000:1. This may help you decipher misleading figures and help compare apples to apples (or PCs to PCs, for those who prefer virus infested equipment).
   
   
4. When selecting a type of HDTV, don’t rely on old reputations. Did accusations of fuel tank explosions unfairly ruin the reputation of the Ford Pinto? Okay, so maybe that's a bad example. A better example of old reputations, however, has plagued the plasma television. Plasma was the first flat panel to hit the market and originally had issues with burn-in and longevity. Today, most high quality plasmas use techniques to avoid burn-in and have life expectancies similar to LCDs. Additionally, projection DLP televisions have had problems with “rainbows” appearing during quick movements. This problem has been addressed on newer models through the use of higher speed color wheels. Yesterday’s information can become today’s myth. Recent research is your best bet. Again, for more information on the various HDTV types and their respective advantages, refer to High Def Alphabet Soup.
   
   
5. The pricey Full HD 1080p resolution isn’t always the best bet. When I gave a friend a coat hanger to help retrieve keys from a locked car, I cautioned him not to break a window. He told me that wouldn't be an issue because all of the windows were rolled down. Lesson: although we try to help, it sometimes just doesn't matter. A person with 20/20 vision that views a 50” television at 10 feet away will likely be unable to see a difference between 720p and 1080p. Viewing a 60” television, however, increases the size enough that a 1080p resolution will likely be distinguishable. Viewing distance and television size play an important role in determining if there is any benefit to a Full HD 1080p screen. Keep in mind that an investment in Full HD is an investment in the future. Currently there are no HD television broadcasts in 1080p so the only way to benefit from this higher resolution is through specially marked HD-DVD players, Blu-Ray players or games for the Xbox 360 or PlayStation 3. For a more detailed explanation of screen sizing considerations, as well as a lookup table for viewing distances and recommended screen resolutions, take a look at Size Matters.
   
   
6. The type of cable connection used is important, but it doesn’t have to be costly. When I bought my car, I paid an extra $500 for helium-filled tires. Lighter weight and better fuel economy sounded like a good idea but my spare tire flew away when I let go of the string. Lesson: don't fall for helium tires - and don't fall for expensive cables. There are three good choices for HD video signals. The three-wire component video cable transfers an analog signal, while HDMI and DVI cables transfer digital signals. The only difference between the two digital cables is that HDMI also carries 6-speaker sound signals in the same single cable. While individual circumstances determine whether component or HDMI/DVI provides better picture quality (you should give each a try), HDMI/DVI are the only cables to support Full HD 1080p resolution. Additionally, the analog component cabling is susceptible to signal quality deterioration due to quality of the cable, length of the run, or splitting. For the digital cables, however, The TV either receives the signal or it does not. Any qualified HDMI/DVI cable will provide optimal, lossless picture quality, regardless of price. There is no need spend a lot here, especially if you have moderate runs of cable.
   
   
7. Placing an HDTV in your home does not mean that everything you watch will have crystal clear detail. HDTV has tremendous capabilities, but it can't provide a quality picture from a poor source any more than a Porsche can perform with water in its fuel tank. Due to the increased size and pixel count of most HDTVs, a standard definition signal will look poor and all imperfections will become very visible. To get an HD signal from your satellite or cable provider you need to subscribe to their HD service. Keep in mind that not all channels will be in HD and those HD channels may not play HD programs all of the time. Depending on your location, you can also get local channels in HD over-the-air (i.e. from an antenna). Although standard DVDs are not in HD, they can look pretty darn good using an upconverting DVD player that translates the image to near-HD. The HD-DVD and Blu-Ray players, however, are your best bet for true HD movies on disc. For gaming, the Xbox 360 and Playstation 3 have HD output, but Nintendo’s Wii does not. Remember that component, HDMI, or DVI cables are needed to carry that HD signal (you won’t get it from a composite or s-video cable) and HDMI and DVI are required for 1080p. Without an HD source or HD cabling, you're just putting water in the fuel tank. For more, read Hi Def Jam.
   
   
8. A widescreen television will not eliminate all black bars. Although this is what I have termed a "pain in the aspect," it's important to understand why black bars appear. The aspect ratio of HDTV is 16:9, which means that for every 16 units wide, the screen is 9 units high. If you have an HD programming source (i.e. satellite, cable, or over-the-air), the HD programs will fit perfectly on your new HDTV display. Most television programming, however, is still in standard definition and the boxier 4:3 aspect ratio. This will give black bars at the side. Additionally, movies are typically shot using wider 1.85:1 or 2.35:1 theatrical aspect ratios. These movies will have black bars at the top and bottom of an HDTV. Zooming or stretching the image can eliminate the black bars, but you should be aware of the mismatch in aspect ratios and distorted images. Visit my earlier post, Pain in the Aspect, for more detail on the subject.
   
   
9. Surround sound is part of the HDTV package. Most ladies won't purchase a new dress without new pumps to complete the package. The same accessorizing should be done when creating your high definition home entertainment system. Don’t forget to include an audio receiver capable of 5.1 surround sound output that comes with HDTV. Most HDTV sources will send sound output to five speakers plus a sub-woofer (for deep base sounds). The HDMI cable connectivity not only passes an HD video signal, but a 5.1 surround sound signal, too. All of this is contained in the single cable, making it the connection method of choice. Using an HDMI cable to connect an HD cable/satellite box to an audio receiver and then to your HDTV will likely bring superior video and sound to your television viewing experience. It also allows the receiver to facilitate video switching between many sources (cable, satellite, video games, over-the-air, DVD, PC, etc.) for those TVs with limited inputs. The receiver can really be those purple pumps that complete the appearance. Look for a future post from me regarding receivers with this capability.
   
   
10. You should place the TV as close to eye-level as possible. Ergonomically speaking, you don’t want SPS (short person syndrome), a phenomenon resulting from having to look up for extended periods of time. This means that mounting your plasma above the fireplace will likely have results similar to exhaustively comparing HDTVs: a royal pain in the neck. For most situations, the middle of your television screen should be around four feet off the floor. If you have a large viewing distance, you can get a little higher. Additionally, a projection television such as a DLP, LCD Projection, or LCoS gives its best picture when viewed from eye-level. While these projection televisions have a broad side-to-side viewing angle, their picture deteriorates quickly when viewed vertically off-center. More viewing angle information is provided in High Def Alphabet Soup.

High-Def Alphabet Soup: PDP LCD DLP LCoS! What is the Best Type of HDTV for Me?

So, you want to buy an HDTV? I sometimes think it is easier to buy a car than a new television. All cars use the same type of internal combustion engine and adhere to measurement standards that allow for comparison (i.e. horsepower and gas mileage ratings). In the HDTV arena, things seem to be mushier. Some manufacturers will decide to publish viewing angles and brightness measures…and others will not. Attributes like picture quality and color vividness are just plain difficult to measure and communicate. Additionally, a manufacturer may list a contrast ratio, but fail to mention whether it is a dynamic or static. I can’t decide if comparing televisions is more like herding cats or nailing Jell-o to a tree. But that is not going to stop me from trying to establish some basic guidelines to compare types of HDTVs. Just keep in mind that there is no replacement for your own first-hand evaluation of any television's picture.

The one part that I will spare you is all of the behind-the-scenes, didn’t-need-to-know, I-couldn’t-care-less detail of how each technology works. I’ll skip over the details of how electricity between plates of glass will excite gases to a state of flatulence, emitting a spectrum that is tantalizing to the senses. Most folks don’t need to know that millions of mirrors the size of flea dandruff turn on hinges that are thinner than a pubic hair and reflect light in a bazillion colors ranging from back-of-the-throat mucus green to falling-off-a-cliff-to-my-death pale yellow. I will spare you the detail. You will thank me.

Another thing to understand is that evaluating TV types is like playing pin-the-tail-on-the-donkey with the donkey on a racing car. The moving target requires constant re-evaluation. Each of the five HDTV types discussed here have distinct advantages and disadvantages, but manufacturers work to address these issues and improve upon prior models. The plasmas have addressed their prior burn-in issues. Newer LCDs will start having new features to improve motion clarity. DLPs have worked to eliminate its rainbow effect. Yesterday’s rules of thumb can quickly turn into today’s myths.

Flat Panel: PDP & LCD
Let us start our discussion with the cream of the crop, the flat panel televisions. If you want a wall-mountable television (or just something really thin), then Plasma or LCD (liquid crystal display) will do the trick at about 4 inches of thickness. Both continue to improve upon their deficiencies, making the differences noted here smaller than ever. Plasma Display Panels (PDP) generally have deeper blacks and better color, but LCD TVs are brighter, making them better choices for well lit rooms. LCD televisions display static images better and continue to be the choice for PC connectivity. Quick motion display, on the other hand, is typically better on the plasma. At the last Consumer Electronics Show, however, many manufacturers showed interpolation methods to improve motion clarity on LCDs. In the near future, look for features like Clear Motion (JVC), Natural Motion (Philips), and – the award for the longest name – Motion Compensation Frame Interpolation (Samsung and Sharp). While LCDs are more prevalent for TVs 37" and under, Plasmas are still more popular in the over-60" range. The sweet spot of the market, displays of the 42" to 50" size, is where the greatest competition exists between the two technologies.

Rear Projection: DLP, LCD Projection, LCoS
If keeping your wallet fat is more important than making your television ultra-thin, then rear projection televisions may be the best option for you. These may be deeper than flat panels, but at 11" to 18" in depth, they are much shallower than your father's rear projection. Three main technologies dominate: DLP, LCD projection, and LCoS. While each has advantages and disadvantages, the DLP (digital light processing) appears to have the slight edge with deeper blacks, a good display of motion, and great capability of displaying still images from a PC. This technology from Texas Instruments, is the one touting millions of tiny little mirrors. Additionally, DLPs continue to dominate the very large 60”+ market. In the past, DLPs have been plagued by "rainbows", infrequent color streaks seen by some viewers. Newer DLP models with high speed color wheels have addressed this problem. LCD projection televisions have grown in popularity and are very price competitive near the sweet spot. The LCD's "screen door effect", a phenomenon where you can see the space between the image pixels, is only seen up close and will diminish with 1080p output. The LCoS (liquid crystal on silicon) technology has been sporadically used among manufacturers, and now has been rebranded as SXRD (Sony) and HD-ILA (JVC). With only these two major manufacturers left, LCoS has been kept out of the limelight. It is hard to go wrong with a good quality set using any of these technologies. They have all come a long way and provide outstanding pictures.

Viewing Angle
Besides console depth, one of the biggest differences between flat panels and rear projection TVs is the viewing angle. This term describes how far off-center you can view the television before you start to see deterioration of the image color and brightness. Plasmas and LCDs have horizontal viewing angles around 178° (note: be suspicious of any figures greater than 180° - this means that you see a good image when you sit behind the screen). The rear projection models suffer in this area, with horizontal viewing angles in the range of 130° to 160°. This, I argue, may be good enough for just about anyone. Any viewing position beyond this range just sucks anyway. If you are sitting at the outskirts of a 120° view, your image is significantly distorted, appearing to be half the width of an image viewed from the front (see graphical illustration). Any horizontal viewing position beyond the capability of TVs described here is just a poor place to watch HDTV.

The viewing angle of greater concern is the vertical viewing angle. For plasmas and LCDs, this continues to hover around 176°. This means you can practically have the TV hanging from the ceiling directly above you and you will see a colorful, bright picture (albeit scrunchy from the angle at which you are viewing). The rear projections, however, start to have significant deterioration 20°-30° above horizontal (i.e. a 40°-60° total viewing angle). At a viewing distance of 8 feet, that can be as little as 3 feet above eye level. Ideally, for ergonomic reasons, you want the TV to be as close to eye level, anyway. In making your decision, however, you need to keep in mind that rear project televisions have limitations on how high the TV can sit.

The Chart
Below is a chart that summarizes the main features of HDTVs and their relative ranking among the television types. Black level and brightness help make up the contrast ratios. Be careful when reading manufacturer specs on contrast ratios. A dynamic contrast ratio looks at the brightest vs. darkest points over time, where the static contrast ratio evaluates this for a snapshot in time. Very high dynamic contrast ratios are easier to achieve than static ones. An outstanding static contrast ratio may be 1,500:1, while it is not unusual to see a dynamic contrast ratio over 10,000:1. The criteria "XL Sizes" refers to the ability of the technology to delivery very large (60"+) televisions. Lastly, the "Price/Size" attribute describes how large of a screen you can buy with your dollar, regardless of other features. An overall rating is provided with all criteria given equal weighting.
Conclusion
While the bottom line of the chart shows the plasma technology on top, this is obviously using my choice of criteria and scaling of attribute differences. [Added 07/11/07: My opinion is not isolated, however, as CNETs Best HDTVs Overall had Plasmas in 6 of the top 10 spots.] It is often more useful, however, to consider your particular application and determine which criteria are important for your environment. For example, something as simple as wall mounting would eliminate the DLP technology from consideration. So with your own criteria and the knowledge gathered here, maybe you can make a little more sense of the high-def alphabet soup and create an informed buying decision.