The FlatHDTV Blog

Making the jump from regular TV to HDTV usually means switching from a square-ish screen to a flatter, more rectangular screen. Speaking technically, most of the TV screens we are used to have a 4 to 3 aspect ratio, meaning they are 3/4 as high as they are wide. Almost all HDTV sets have the “widescreen” format, with the slightly more movie-like 16 to 9 aspect ratio.

So, if you want to replace that old Trinitron with a similar-sized HDTV, you’ll need to do a little (very little) geometry to make sure your viewing experience will actually be better.

TV sets are measured diagonally, from corner to corner. So, because of its flatter shape, a 25 inch widescreen HDTV will be wider than a 25 inch regular TV, but will be lower in height. To match the height of a 25 inch regular TV (which is 15 inches, incidentally), a widescreen would need a diagonal measurement of 30.6 inches:

Maintaining the same picture height is important, because there’s still a lot of content out there that is designed for the old 4:3 format. This is what happens to regular content on a widescreen:

So, your new HDTV will need to be about 20 percent bigger, in the diagonal measurement, to display standard content as big as you are used to seeing it. If not, a good portion of the shows you watch will actually be smaller on the widescreen.

Of course, the easy option is just to “go big” with the new set. The extreme sharpness of HDTV, especially 1080p HDTV, makes it hard to go wrong by going too big.

Buying a big-ticket item like an HDTV through the internet is a pretty scary prospect for most people. There are several anxiety issues: Will my stuff get damaged in shipping? What if I have to return it? Will I waste the better part of a day (or two) waiting for the delivery truck? And isn’t it crazy to send several thousand dollars into cyberspace, to someone who may or may not even be a real person?

Those are all reasonable fears. But, the last one is not as reasonable as it was back in the 90s. The rise of major online retailers like Amazon.com has raised online customer service standards to a level where the overall experience, though different, is in many ways better than the experience at your neighborhood electronics store. Let’s look at some of the concerns behind buying online:

• My HDTV may be damaged in shipping. It’s certainly possible. But the policy of Amazon and most other online retailers takes this into account, and gives you several ways to deal with it. With their standard shipping, the delivery person will typically help you take the set out of the box, wait for you to plug it in and see if there is any shipping damage. If there is, it’s a no-brainer- the set goes back and you get a replacement immediately.
• The set may be damaged in a way that is not immediately obvious. Even if you don’t notice anything wrong with the set right away, you can still send it back for a replacement within 30 days, and Amazon will pay for the shipping. And when you think about it, this problem is equally likely when buying from a physical store: the set had to be shipped to the store in the first place, and the store is certainly not going to test every unit for every kind of defect. That means you’re the “test pilot” whether you buy from Circuit City or Amazon.
• I will have to wait all day for the delivery truck. Yeah, this one’s annoying. But fighting traffic and hanging around in a big-box electronics store for several hours can be infinitely frustrating as well.
• It’s easier to talk a salesperson into a lower price. If you’re a genius at haggling low prices out of retail sales managers, you might enjoy the buying process more at a physical store. Unfortunately, while most salespeople can be talked into matching the price you found down the street, they will rarely match the best price you can find online. Beating the other neighborhood stores is one thing, but beating every store on the internet is quite another. And to top it off, Amazon will actually give you a rebate on your purchase if the price of your HDTV goes down within 30 days after your purchase.
• It’s hard to trust a faceless online merchant. Given the speed with which the world is changing, that’s understandable. The best way to get around this one is to start spending more time online, do your research, interact with real people in chat rooms, read industry newsletters, and so on. Once you become aware of the potential pitfalls and the ways to safeguard against them, buying online will feel as natural as putting money in the bank.

For more information on buying HDTV sets online, please visit FlatHDTV.net, a website dedicated to helping you make a wise and informed purchase.

Whenever new, amazing, and mysterious technology appears in the world, a new group of “experts” on this technology often appears out of nowhere. These people are full of good information and have the best intentions, but sometimes they get a little careless with their explanations and promote an idea that seems logical and makes sense, but is actually wrong.

The conventional wisdom behind HDTV tech, magic as it is, includes several of these logical but misguided tips. One goes like this: Plasma TVs contain a weird substance inside the screen, called “plasma”, which is so slippery and sneaky that it could leak out of the set if you lay it flat on the floor or in the back of your car. This reasoning supposedly explains why many retailers have a strict policy against shipping a Plasma TV any way except vertically. Some customers have even been obligated to choose an LCD over a Plasma because the back of their car wasn’t tall enough to take it away from the shop in a vertical position.

The real reason behind that policy is that a Plasma TV has a relatively fragile construction, with two panes of glass mounted very close to each other. If one was resting horizontally in the back of a truck, and that truck bounced over a speed bump a little too fast, the panes could bounce a little themselves and squeeze what’s in between.

What’s in between is not a pool of mysterious liquid, but an array of tiny cells that contain a special kind of gas. When the computer inside the TV tells them to, these cells light up like tiny neon lights, because the gas inside them is excited into what’s called a “plasma state”. If some of these cells get damaged by transport, there’s really no way to fix them. Laying a Plasma TV carefully down on your living room floor, however, won’t do any harm at all. Just don’t step on it.

Here are some references, in case you need a little more convincing:

http://www.dtvcity.com/plasmatv/plasmatv-leak.html

http://www.hometheaterblog.com/hometheater/2006/06/plasma_tv_sales.html

http://www.answers.com/plasma+display?cat=technology

HDTV merchants have two important jobs: to bring you the best technology available, and to help you understand exactly what it is. One way to help you understand new technology is to come up with a simple, descriptive name for it. But sometimes the names are a little too simple, sometimes they aren’t descriptive enough, and sometimes they are downright misleading.

Here are five common HDTV terms that can be misleading or unclear:

Native 720p/1080i Display
Most HDTV displays have either 768 or 1080 rows of pixels, and a few have 900. And all HDTVs have an inherently progressive display, so the most common native resolutions are 768p, 900p, and 1080p. So, when a manufacturer or merchant claims that an HDTV is “native 720p/1080i”, it usually means that those are the highest resolutions it can handle, and the input is scaled and de-interlaced to fit a 768p display. Some DLP HDTVs, however, do have a native 720p display.

HDTV Antenna
There’s no such thing as a dedicated HDTV antenna. Over-the-air HDTV broadcasts use the UHF spectrum, just like public access TV. So, any UHF antenna will work.

Full HD
This refers to a 1080p display with a screen resolution of 1920 x 1080 pixels and the ability to display 24, 30 or 60 full frames per second. The term is not wrong, but it implies that 720p or 1080i content is somehow incomplete. Since neary all HD content these days is still 720p or 1080i, that would be kind of depressing for HDTV owners.

HD-Ready
Ready for what? HD-ready means the same thing as HD monitor. It is an HDTV without a built-in tuner, so an external ATSC tuner, or a cable box, will be needed to receive broadcasts. If you only intend to use the HDTV for gaming or DVD watching, it might be better to save a few hundred dollars with an HD-ready TV.

1080p Upconverting DVD Player
Many DVD players claim to upconvert content to 1080p, as opposed to 1080i. This is unnecessary, since all HDTVs have progressive displays, and there’s no visible difference between content upconverted to 1080i and content upconverted to 1080p. The transfer from “i” to “p” is called de-interlacing, and this task is performed by the TV anyway. The only benefit would come if it’s a low quality HDTV (with a poor de-interlacer) and a high quality DVD player with a good de-interlacer.

Let’s start by explaining just what a 720p or a 1080p HDTV is. For some background information, you can take a few minutes to read this: HDTV Basics

Every HDTV on the market today has either 768 or 1080 rows of pixels in its display, and it displays them progressively. The ones with 768 are commonly called 720p/1080i sets, because those are the highest resolutions they can handle. If they receive 480p or 720p input, those 480 or 720 rows of pixels in the signal are spread out (upscaled) across the 768 pixel rows of the display. If they receive 1080i input, the signal is squeezed down (downscaled) to fit into the 768 rows and de-interlaced to match the progressive nature of the display. The downscaling process causes the signal to lose a little bit of information and, thus, resolution.

The sets with 1080 rows of pixels are the 1080p sets. They can accept 480p, 720p and 1080i content too, but the 1080i content will simply be de-interlaced and not downscaled, so every pixel will be displayed in its full glory. But if the input is 1080i and not 1080p, the de-interlacing process will slow the frame rate from 60 frames per second to 30. So if you’re watching sports or other fast-moving content, 720p input might look a little better than 1080i, and a 720p set would have no disadvantage compared to a 1080p set.

If you’re obsessed with the idea of buying a 1080p set, here are three factors that might make you reconsider:

• input source: You will only take full advantage of a 1080p set if you have 1080p input, and this is still fairly rare. 720p input, which you get from broadcast, DVD players, and even most HD-DVD and Blu-Ray players, will look just as good on a 720p set. 1080i input will look a little better on a 1080p set, though, because it won’t be downscaled to a lower resolution.
• screen size: One result of changing from 720 rows to 1080 rows is that the pixels will be smaller on the same size screen. On sets smaller than 50 inches, the pixels are incredibly small no matter which resolution you have, so there’s really no advantage to 1080p on these sets at normal viewing distances.
• other quality factors: All else being equal, 1080p resolution is better than 720p. But the thing is, all else is usually not equal. Other factors like contrast ratio, black level, color saturation, a high quality signal, and overall quality of the HDTV are actually more important than the resolution of the screen. It would be foolish to choose an inferior and probably more expensive set just because it has one cool feature.

If you’ve been researching HDTVs, you’ve heard about a nasty little problem, unique to Plasma and CRT sets, called burn-in. That’s when your $5000 Plasma screen gets imprinted with the ghostly image of a logo or menu box because certain parts of the screen have aged faster than the rest. But if it’s such a big deal, why do people keep buying expensive Plasma HDTVs? Is burn-in really worth worrying about?

Burn-In Susceptibility, 2007
The HDTV industry is very competitive these days, and Plasma manufacturers are really starting to feel the heat from the LCD industry. So, you can bet they’re doing everything they can to eliminate burn-in. Screen technology has improved to the point where proper use of the TV will definitely not cause a problem, but careless use just might. And several of the new Plasma HDTVs, like the Samsung HPT5064, have a “screen burn protection mode” built into the TV to repair mild damage.

Image Retention vs. Burn-In
Image retention is a common thing that you have likely seen after turning off a CRT television at night: the last image to appear on the screen stays there for a while after the TV is off, then fades away slowly. This is caused by a charge build-up in the phosphors (the glowing picture elements in the screen), and will go away after the display has been powered off for a little while. This is common in Plasma TVs too, but isn’t something to worry about.

Burn-in, on the other hand, is semi-permanent. Since it results from uneven aging of the phosphors, the “burned” image will persist forever. It can be caused by spending a lot of time watching stuff in 4:3 mode, watching a news channel with a stationary “stock ticker”, or playing a game with stationary screen elements. There are ways to fix a burned-in screen, but an ounce of prevention is worth a pound of cure: follow a break-in procedure when the set is new.

The Break-In Procedure
If you’d rather be safe than sorry, you’ll need to go through a simple break-in process when the TV is new. Here are some guidelines from a report commissioned by Panasonic:

• Make sure the display is in a viewing mode (aspect ratio) that completely fills the screen (there are often three or more settings from which to choose). The panel is shipped in this condition, in what is called the “Just” mode.
  
• Turn down the picture control (contrast) to 50% or less.
• Briefly engage the 4:3 mode to confirm the side bars are set to mid-gray (there is usually an adjustment in the Setup menu that takes the sidebars from black to gray) to minimize the chance of burn-in.
• Return the set to a “full screen” (Just, Zoom, Full) position during the
  first hundred hours of use.
• During the first hundred hours of use it is best not to view the same
  channel for extended periods. This should prevent channel logos and
  other fixed images found on some channels from being retained.
• Avoid any static images (video games, computer images, DVD title
  screens, etc.) during the hundred-hour break-in.
• Continue to retain the picture setting at 50% or less.
• Limit the use of 4:3 aspect ratio mode (traditional picture size that does not fill the entire screen) to 15% of viewing time.
• Limit the use of static images (computer, video games, etc.) to less than 10% of viewing time.
• After one thousand viewing hours, panels are much less likely to experience image burn-in.

© 2004 Panasonic

The Bottom Line
HDTV experts agree now that burn-in is a vastly overstated problem. Complaints come from less than 5 percent of all users, but those people are understandably upset and vocal when the centerpiece of their home theater is ruined. Buying a late model Plasma, using a break-in procedure, and avoiding certain viewing habits should reduce the chance of damage to just about zero.

For more information on Plasma and other HDTV technology, check out FlatHDTV.net.

Contrast ratio is one of the specs that people seem most interested in when researching a new HDTV. All else being equal, higher contrast ratios mean higher prices, and, by implication, a better overall picture. Simply, the contrast ratio is the difference between the darkest black and the brightest white the screen can display.

This has a lot to do with the quality of the HDTV, and also with the way the manufacturer chooses to measure it, so maximizing the contrast ratio by choosing one make of HDTV over another is a dubious plan. But, there is one sure way to improve things, regardless of the TV specs:

The key is to “trick” your eyes a little bit. The aperture of your eye’s iris will constrict in bright light and dilate in darker light, right? If your TV room is completely dark, your eyes will be dilated and sensitive to low amounts of light, so you will have to turn the brightness down on your screen to make the black areas appear totally dark. This also reduces the brightness of the bright scenes, thus reducing the apparent contrast ratio.

If you place a dim light source, like a small lamp, behind the TV and shining on the wall in your otherwise dark room, your iris will contract a bit and allow you to turn up the brightness a little. You will still see black as completely black (as long as you don’t make it too bright), and will have more brightness in the bright scenes, thus increasing the apparent contrast ratio and making the picture look better.

Constricting your iris also increases the sharpness of your vision. And the dim, diffuse light will not cause glare on the screen like a direct or overhead light would.

For further information check here: HDTV Tips