Home Theater Review

Everything You Need To Know About High Definition HDTVs

1.0 Types of HDTVs
There are a number of types or form factors of HDTVs available today to consumers. Video projectors aren’t technically “flat HDTVs” but the early CRT HDTVs started as projectors paired with a video screen.

1.1 CRT or Big Screen HDTVs
Besides video projectors, the first HDTVs were in the form of a “big screen” HDTV. Many used CRT technology basically hosting a video projector mounted vertically and bounced off of a mirror inside of a large physical TV. Later both D-ILA and DLP technologies were used to replace CRT technology with smaller, brighter digital video projection engines. Many enthusiasts feel that rear projection, big screen HDTVs still to this day represent the best value for the consumer even if they aren’t technologically long for the world.

1.2 Plasma HDTVs
Many home theater enthusiasts think that despite cost that the best performance from any flat HDTV comes from a plasma. Period. End of discussion. The black levels are often better but LED-LCD sets can be thinner and brighter. The right TV for you depends on your room. If you can get your room pretty dark, a plasma HDTV is a good option.

1.2.1 The Basics of How a Plasma Works
The way a plasma HDTV works is that "noble" gases (remember those from chemistry class?) interact with cells in between two relatively large pieces of glass. When electricity is introduced to the gas and cells, they turn into plasma that has phosphors that can emit light.

1.2.2 Cultural and Economic Impact of Plasma HDTVs
Flat HDTVs (and even EDTVs - which were mostly non-HD plasmas), led by plasma technology, changed the way the world looked at the all-important component known as a television. Gone was the hulking rear-projection set that took up volumes of increasingly valuable living room real estate and in was a wafer-thin HDTV measuring a mere four inches thick that could hang on the wall like a painting.

In the early days of plasma TVs in the marketplace, the sets were only for the rich, as a 50-inch plasma HDTV cost upwards of $20,000. However, as mainstream consumers bought more and more of the TVs, the price dropped precipitously. Today, nearly seven years since the commercial launch of plasma TVs, sets are affordable for nearly everyone and sold in easy to access stores like Costco and Wal-Mart for well under $1,000 for a sizable set.

Some AV industry analysts suggest that the rise in popularity and the ensuing fall in price of plasma HDTVs was the cause of death for many of the brick-and-mortar specialty audio dealers. These dealers loved how easy it was to sell the sexy new video technology, but once the prices dropped below a certain threshold (some say $4,000 per set), these dealers couldn't make money working on the lower margins at low volumes. Enter in Wal-Mart and Costco, along with Best Buy and Amazon.com . With tremendous downward pressure on the price, the margins on flat HDTVs shrunk to less than three percent in some cases. Dealers who got away with selling 50 percent profit margin audio products could no longer make their businesses operate effectively on these new, lower margins, and many closed.

1.2.3 Installing a Plasma HDTV
Even though a plasma HDTV looks like a picture you can hang on the wall, it is a heavy, sensitive video display device that will be rendered useless if it is dropped, and therefore it requires firm mounting, wherever it is placed.

There are mounts for plasma HDTVs that can get the HDTV close to the wall. Other mounts allow the set to move on an arm to accommodate different seating positions and heights.

Some people build small niches in their drywall to accommodate the depth (including a little room to breathe) around their set.

In very high-end installations, some clients use a lift built into a cabinet that can stow the plasma under the bed and slowly swing the set up to a viewing spot right at the foot.

1.2.4 Which is HDTV Better: Plasma or LCD?
The term "plasma" has become the ubiquitous term for a flat HDTV, despite the fact that there are two major technologies driving the flat HDTV market today, with others being developed for future technologies such as OLED.

Plasma HDTVs are thought by video calibrators to have the best "blacks," as promoted by the now defunct line of Pioneer KURO sets (KURO means black in Japanese). In a darker room, the blacker blacks allow for more contrast, which creates a more three-dimensional-looking HDTV image.

LCD HDTVs are generally sold for premises that might have more ambient light in the room, as they tend to be able to make a brighter picture than other HDTV technologies.

To date, both formats have been honed to a point where they make fine HDTV images, so most people pick one of the best sets in the biggest size they can afford. If you pick a premium brand, get it professionally calibrated and hook up a Blu-ray player for a 1080p video source - you can't lose.

1.3 LCD-LED HDTVs

1.3.1 How Does an LCD HDTV Work? Much like plasma has a gas that is excited by electricity, which morphs it into quasi-solid plasma between two sheets of glass, an LCD HDTV liquid crystals stored in between two sheets of polarized glass. These crystals get "twisted" or "untwisted" to make the full range of light to dark. The in-between areas are where an LCD creates grayscale. A fluorescent light is used to create color, starting with the whitest of whites and, as the crystals are untwisted, they can create millions of different colors between the fully twisted and fully untwisted elements. This can result is as many as 16-plus million colors that can be reproduced by a modern 1080p LCD HDTV.


1.3.2 All About Refresh Rate
An LCD HDTV's refresh rate is the number of times a display's image is refreshed per second. The refresh rate is almost uniformly measured in Hertz. A refresh rate of 75 means the image is redrawn 75 times per second. 

Scientists who study the eye say the tipping point for the refresh rate is about 70 Hertz. However, most of today's LCD HDTVs have refresh rates of over 120 Hz. The effect of 120 Hertz refresh rates includes a TV that looks smoother and less blurry, even during complicated movement scenes in movies and/or other fast-moving images. Sony recently showed 240 Hertz refresh rates on their LCDs.

2.0 3D HDTV
3D HDTV was thought to be the technology that kept the consumer electronics party going through the brutal housing recession that started in 2008. At the box office, James Cameron’s Avatar, was a huge success (surprise, surprise) but beyond this record breaking film consumers weren’t really drawn to 3D as Asian electronics companies thought they would be. Not everyone physically likes or can see 3D. Some get nauseous. Others get dizzy. Some don’t like the way movies are produced in 3D while the overriding factor with 3D is the cost of replacing a 1080p HDTV with a 3D unit. Today 3D is included on many sets as are the glasses needed to watch but the high cost of 3D Blu-ray movies also is a limiting factor. One bright spot for 3D is in the booming video gaming community where gamers embrace the technology more so than home theater enthusiasts.

2.1 Anaglyph 3D
You know the concept of anaglyph 3D even if you haven’t heard the word. Anaglyph 3D is the traditional, non-active way to see 3D. Think of a young couple in a 1950s movie theater watching a movie in 3D and you’ve got the concept of 3D. Todays movie theaters still use anaglyph but they’ve upgraded to recyclable plastic glasses from the tacky paper ones.

2.2 Active 3D
Active 3D is what today’s flat HDTVs mainly use to power their 3D trickery. These glasses have a much higher cost than anaglyph glasses and also require some form of power which normally comes in the form of rechargeable batteries. Many consumers have complained about the $100 plus cost of glasses paired with the lack of standards that leave consumers with different brands of 3D HDTVs not able to use their active glasses from say a Panasonic 3D plasma on another 3D HDTV in the house from another company like Samsung, Sony or others.

2.3 Autostereoscopic 3D
Autostereoscopic as a word could win you Scrabble but in more simple terms it defines the concept of 3D without glasses. There are no Autostereoscopic 3D HDTVs currently in the market today however there are many companies like Toshiba and Dolby who are developing the technology. Recent public displays who that it is possible to give the viewer 3D without glasses but the effects are mutes, you can’t move your head and you must be located in the perfect “sweet spot”. Long term 3D’s potential will be realized when Autostereoscopic 3D makes it to the mainstream.

3.0 Video Calibration
We’ve all toyed with the settings of a television trying to get a better picture. Video calibration is the science of actually using those controls (generally done by a trained professional from THX or the Imaging Science Foundation) to achieve standards set by broadcasters and filmmakers.

There are many advantages to video calibration including getting a better picture, longer life for the HDTV and more accurate reproduction of the content that you watch. Thankfully, unlike audio, video is a pretty exact science thus with professional calibration you can get even a modest HDTV to meet current calibration standards for a pretty affordable price.

3.1 Disc-based Calibration
There are any number of discs ranging from Digital Video Essentials to Silicon Image’s Blu-ray to the Disney WOW setup disc to Monster Cable’s video calibration disc. Many don’t believe that a $20 to $30 calibration DVD or Blu-ray is a “real calibration” and they are likely right however using a disc to “eyeball” your HDTV closer to standards like SMPTE is a good, affordable way to get more from your HDTV investment.

3.2 Professional Video Calibration
Hiring a professional is the best way to get your HDTV to the top standards. For a modest professional services fee, there are hundreds of people nationwide who can come out and get your HDTV dialed into its absolute best, scientific performance. These professionals use calibration tools far more sophisticated than the human eye including computer software and light meters that are pretty hard core.

4.0 Ultra HD and 4K
After the decision to re-brand consumer 4K as Ultra HD was made, the industry began to push the technology at the 2013 Consumer Electronics Show. While 4K refers to a resolution with 4,000 horizontal pixels, Ultra HD does not. Ultra HD is 4 times the resolution of 1080p, but it does not reach 4K, stopping at 3840 x 2160. However, the Ultra HD moniker also allows for resolutions beyond this. So if an HDTV with 8,000 horizontal pixels is released, it could technically be branded an Ultra HD television.

5.0 Video and HDTV Resources
Beyond reading the reviews that are published by HomeTheaterReview.com in this review resource – please feel free to read our Home Theater Education page which covers definitions of many video and home theater terms that can help explain any topics that need any additional insights.

Other Resources

• THX
• Imaging Science Foundation
• Energy Star
• SMPTE