High Def Talk Part I: HD Displays

Background

Let's take a break from cameras, computers, and printing for a bit and take a look at high definition television and home theater. After all, those of us who are interested in the best photographs, camera equipment, computer equipment, and printers are often interested in getting the best picture when it comes to home entertainment as well. I find it interesting when I meet photographers who have some of the most expensive photographic equipment, claim to be home theater or AV (audio-video) fans, yet are still watching a 54 inch big screen TV from the late 80's or early 90's. I've even heard the phrase: "My DVD's look great. How much better can it be?" I'll try to answer that question in this article that is geared toward those of you who have not yet made the leap to HDTV and might be wondering if it is time. If you are an "HD nut" who frequents avsforum, you'll likely get very little out of this article as you are already ahead of the curve.

SD versus HD

What is "high definition" and how does it compare to "standard definition"? Broadcast TV, based on a display format that was conceived in the 1930's in black-and-white and later modified to carry color video in the 1950's, offers a resolution of about 330 x 245 pixels. SD or "standard definition" is a relatively new term that refers to a digital video format of approximately 640 x 480 pixels interlaced (480i). While this is better than the old broadcast standard (and is the reason why standard DVD's look better than TV), 640 x 480 is not nearly enough resolving power for the larger (36 inch+) sets used in home theaters. Just walk up to anyone who is digital photography savvy and tell them that you are thinking about printing a 36 x 24 inch print from a 640 x 480 shot taken with a cell phone. When they're finished laughing and finally get up off the floor, realize that you're doing almost the same thing by watching that 640 x 480 DVD on your old 54 inch TV!

If you live in an area where you are able to get local TV stations on a television with a "rabbit ear" antenna, chances are you already have high definition signals coming through the airwaves to your home. You simply cannot watch them because you don't have a high definition set. High definition comes in two basic formats: 720p and 1080i. 720p is 1280 x 720 resolution and pixels are displayed progressively so that all 920,000 pixels are displayed in each frame. 1080i is 1920 x 1080 resolution but it is interlaced, meaning that only the odd or even lines are displayed with each frame. A newer format, 1080p, is now being supported in many displays but as of this writing, there is very little content that is actually available in the 1080p format so most of the 1080p sets just take a 1080i signal and deinterlace it. Still, 1920 x 1080 is 2 million pixels of resolution. Compare that to the 640 x 480 (300,000 pixels) available on a standard DVD. The best high definition material is over 6 times the resolution of a standard DVD.

In the eye of the beholder

It's difficult to describe how much better HD is when compared to SD. You simply have to see it for yourself. Many compare HD to the feeling of looking through a window at the actual scene. The clarity, texture, and dynamic range are amazing. So much so that once you get used to HD, it is difficult to watch SD! I'm so used to HD now that whenever a football game is broadcast in SD, I literally cringe. SD looks so out of focus and so devoid of detail that it almost gives me a headache when I watch something with a lot of action like a sporting event in SD. Of course, these don't look nearly as good as a DVD due to compression artifacts and the re-processing involved with broadcast SD signals on satellite or digital cable. Upsampled DVD on an HD monitor can actually look nearly as good as high definition even though, technically it is not high definition: most likely 480p (640 x 480 or 720 x 480 progressive). When asked to describe HD versus SD, you'll likely get a different answer from everyone you ask but there's nothing like the first time you see true HD material on a true HD set. It's something you'll never forget!

"Fake" HD

As we know, "high definition" refers to a video format that consists of either 1280 x 720 pixels or 1920 x 1080 pixels. If you walk into a store and they are piping video from a standard DVD player through their sets, you'll know immediately that you are not looking at anything high definition because DVD's are 480p (640 x 480 resolution) and are therefore not considered high definition. Technically, 480p is considered EDTV (enhanced definition TV). EDTV is actually a major advance over SDTV, but it still falls short of high definition. Be aware of sets that are marked EDTV. If it is marked EDTV, it is not a high definition set. Some smaller plasma TV's are EDTV as are some sets marked "high definition compatible". High definition compatible is often used to indicate that the set can decode an HDTV signal, not that the set itself is HD! Suffice it to say that if you are in the market for an HDTV, make sure the store where you are evaluating the sets is piping a true HD signal to the sets and that the set itself is truly HD.

Display types

Different types of displays (LCD's, plasmas, DLP's) have their advantages and disadvantages. Any true HD set you buy today will certainly look many times better than a standard TV, but what type of set is right for you? Let's take a quick look at a few of the most popular display types and look at their advantages and disadvantages.

Plasma: Plasma televisions are actually not that dissimilar from older tube sets. They use phosphor just like the old tube sets. The difference is in how the phosphor is excited (lit). In a CRT (tube television), a beam of electrons scans the phosphor, lighting "pixels" in sequence. In a plasma TV, the phosphor is lit with individual electrodes under each pixel. The obvious advantage is size. Since plasma TV's don't need any projection, they are made as flat panels that are very thin and can be hung on walls or used in cramped spaces. Plasma TV's are some of the most vibrant sets with excellent dynamic range (rich blacks and bright whites) and are currently the best technology on the market for viewing at an angle, as plasma televisions don't fade when viewed off-center. Almost all consumer plasma sets as of this writing use the 720p HD format. That is, they have a resolution of about 1280 x 720 pixels for plasma sets 46 inches and larger. Due to limitations in the plasma technology, 1080p (1920 x 1080 resolution) plasma sets are just now being introduced to the marker in sizes under 60 inches, so if you are looking for a plasma set that is 60 inches or smaller, you'll be getting a 720p set unless you want to pay $10,000 or more. Burn-in, where static images can be "burnt" into the screen permanently, is not much of an issue on the latest plasmas but you should avoid static images as much as possible during the first ~100 hours of operation. In addition, if you plan to do a lot of video gaming, an LCD may be a better choice because static images like radars, scores, and health meters can eventually be burned in if left on a plasma screen for extended periods of time.

LCD: For years, LCD (liquid crystal display) televisions have struggled to compare to plasma TV's. The most recent LCD models have all but caught plasma TV's on every front except off-angle viewing. Today's LCD's offer less fade when viewing from an angle, are brighter, have better blacks (better dynamic range) and have better response times, meaning that they don't "blur" fast moving objects like older LCD sets. In addition, it's easier to manufacture smaller LCD screens (under 60 inches) with a higher pixel count compared to plasma TV's, so there are a fair number of 1080p (1920 x 1080 resolution) LCD sets available at the 55 inch and smaller sizes, making them boast higher resolution than plasma sets. There is still some color and contrast fade when moving to off-angle viewing, but the very latest models show a lot of promise here, with very little noticeable fade when viewing from an angle. Things tend to change quickly as far as display technology, but as of this writing, some of the latest 1080p 50 to 55 inch LCD sets top the list as the highest quality HD sets available with the least number of drawbacks (such as uneven lighting, ghosting, "hot spots", seen with many projection type TV's)! Like plasma displays, LCD's are flat panels that can be hung on a wall and they are often even lighter/thinner than plasmas. Screen burn-in is not an issue with LCD displays, making them the display of choice for gamers.

DLP: DLP (digital light processor) televisions have been around for about a decade. They are a form of rear projection television that uses tiny mirrors to throw light on the front screen. These sets are not flat panels and are therefore a bit bulkier than plasma or LCD TV's, but they can be very cost effective. They tend to be cheaper than plasma or LCD sets of comparable size and they do offer an excellent picture. I'm not a big fan of projection televisions as they tend to produce a less evenly lit picture and my eyes are quite sensitive to blooming, color inconsistencies, fade, and the "rainbow effect" that you can sometimes see on DLP sets. Any projection set will tend to be a bit less sharp than a flat panel set due to the fact that light is being "thrown" at a distance rather than being created at specific points on a static (non moving) panel. As with LCD panels, screen burn-in is generally not an issue with DLP displays.

SXRD: SXRD, short for Silicon X-tal Reflective Display, is a Sony acronym for a technology known as LCOS (liquid crystal on silicon). It is similar to DLP in that it uses a reflective surface but instead of using mechanical mirrors, liquid crystals are used to reflect the light from the projector onto the front screen. Again, this is a projection TV so it is not a flat panel and will take up more space than a plasma or LCD TV. Sony SXRD sets typically have a better picture than DLP sets and some people believe they have a "film" or "movie theater" look unrivaled by any other display type. As I mentioned under DLP, I'm not a fan of projection TV's just because I'm sensitive to the contrast and color fade that occurs when viewing projection TV's at an angle. I also miss the silky smooth uniformity of plasma and LCD sets when I have to move (walk) in front of a projection set as I can always detect the bright spot from the projection lamp(s) moving across the screen with me. Others may prefer SXRD technology over plasma and LCD due to the film-like look appearing less like "pixels". Here again, beauty is in the eye of the beholder. Since SXRD displays are basically LCD on silicon, they generally do not suffer from burn-in.

Bottom line: The bottom line on choosing a display is to first determine whether or not the display is truly high definition. To be high definition, the display must have 1280 x 720 pixels or more and should have an "HD" logo. Stick to models marked HDTV and shy away from models marked EDTV. When you have limited your search to HD displays, let your eyes be the judge. Different people look for different things in a display. Some pay more attention to contrast and saturation while others are more critical of resolution, pixels, and sharpness. The real bottom line is that you should pick the set that looks best to you! Keep in mind that different display types work better in different environments with plasma and LCD displays generally being better in rooms with bright lighting (sunlight entering a window for example). Once you've picked your favorite set in your price range, it wouldn't hurt to leave the store and do a little research. Try Googling the model number or even the model number and the word "problem" to see if other users are experiencing any common issues with that set. Sometimes you'll find complaints of color blooming, ghosting, banding, or other issues and that may give you some things to double check before you buy. Any common problems are usually described or displayed with enough detail that you'll be able to look for the problem in the set you picked to see if it is an issue for you.

HD Content

Before buying an HD display for your home theater, it would be wise to be aware of the HD content that is actually available to you. Broadcast HD is accessible in most locations in the form of digital cable, satellite, or fiber services. If you have cable TV, chances are your cable provider offers "digital cable" that includes at least a few HD channels. Note that the fact that a channel is "digital" does not necessarily mean that it is HD (it could be SD just broadcast in digital format), so be sure to ask your cable provider how many/what channels are offered in true HD and/or check out their web site. If you are interested in cable HD, some displays offer a cable card feature, so you might want to check compatibility of the TV with your cable service, although that is not a necessity since your cable provider can provide you with an (external) cable box.

Verizon FIOS is a promising fiber TV and internet service that has a lot of promise, but it isn't likely to be available in your area as coverage right now is extremely limited. To find out if FIOS is available in your area, check here.

If you live in the boonies and don't have cable or FIOS service and/or you don't like the selections offered by those services, there's always satellite TV. Right now, Dish Network has the greatest selection and number of true HD channels available in any service offering high definition content since Dish has taken over the Voom HD satellite service. DirecTV also offers HD channels and while they plan to offer many new HD channels in the next year, their selection of true HD channels is more limited as of this writing. If you already have one of these services but you don't get high definition channels right now, you may need new equipment and you may be required to pay an install fee and a small monthly fee to access the HD channels. Check the web sites of the service in question for more info. All services that offer HD content also offer DVR's that can record HD content as well. When choosing a satellite provider, find out whether or not they offer your local (ABC, CBS, NBC, Fox) channels in high definition via satellite. If not, you may be required to get these OTA (over the air) with an antenna connected to the satellite receiver.

If you live within say 30 miles of a city that has local TV channels, chances are you can get some HD content for free (or at least with no monthly charges). If your display didn't come with a built in tuner that can handle "over the air" TV broadcasts, you'll need to buy a tuner that is capable of receiving high definition broadcasts. What you're looking for is a tuner that is labeled as an ATSC tuner. In most cases, a good indoor antenna is sufficient to receive these channels but if you need an antenna, check to see whether you need a VHF or UHF antenna as HD can be used on both frequency ranges. To see how far you are from various TV stations and what type of antenna you need, try visiting antennaweb. You can simply enter your ZIP code and click "Submit" to see the TV stations near you and the antenna type/size needed. Note that channels with a sub-channel (2.1, 11.1, etc.) are "DT" or digital television. Those are the channels that are broadcast in digital format and are likely to offer high definition content although the DT designation does not guarantee that the channel broadcasts HD.

After broadcast HD comes HD content on other media such as HD-DVD and Blu-Ray. Movies are starting to be released in the HD-DVD and Blu-Ray formats now and most online rental services offer the formats at no additional charge over standard DVD's, but selections are limited and the two formats are still competing with no clear winner in the format war. In addition, current HD-DVD and Blu-Ray players can be expensive (about $500 for HD-DVD players and $1000 for Blu-Ray players) and are relatively slow to start up. There's also talk of players in the future that may be able to play both formats, but no "hybrid" players exist as of this writing. Simply put, it may be best to wait a year to see where these technologies are going unless you have deep pockets and just want some HD to show off because you are limited as far as HD content. A good upsampling (standard) DVD player may be a more cost effective investment until the HD media markets settle a bit.

Summary

While this article focused on high definition displays to be used in home theater applications, there is certainly a lot left untouched. If you are left wondering about which connections to use, HDMI versus component, audio options, HD-DVD versus Blu-Ray, backlighting, or other aspects of home theater, those aspects will have to be covered in a future article. And again, this article is aimed at those of you who have been wondering if it might be time to make the leap to HD and some things to look for at the starting line. Just be warned that if you are easily obsessed, home theater and "high definition" can be quite expensive. While my own setup is quite modest, I've seen people spend $85,000 or more on true home theaters! On the other end of the spectrum, it is possible to set up a good HD theater for $3,000 with $1,500 being about the bottom entry point, so there's something for everyone. To start, try to pick a store that has a home theater section with a large selection of displays and knowledgeable/helpful staff. Let them help you but don't let them push this week's sale on you. Take your time, use the information from this article, and make the decision that is best for you and I believe you'll find that HD will quickly become a necessity in your home theater. If you're reading this article soon after release, you may still have time to get that HD set for the big game! :-)

-- Mike Chaney