Deciding which LCD TV to buy?

Welcome to Buy LCD TV- your source for getting the best deal on a new LCD TV online today!

LCD TV- Technical Facts in Plain English

Do you have a new TV in mind, yet find all the technical specs and mumbo-jumbo bewildering? You’re not alone. Here’s a few facts to help clear things up.

Just like a computer monitor, the display of an LCD TV has a given resolution. The ‘resolution’ is essentially how many little squares the display breaks down into, just like the pixels in a digital photograph. The resolution is measured by the width of the display x the height. Another component of the resolution specs for a high definition TV has to do with how quickly the entire field of individual pixels are given new instructions each second. We’ll cover more on this in a minute.

The next technical term to grasp is the ‘aspect ratio’. This is basically how wide the display area is vs. how tall the display is. Think a ‘wide screen’ dvd vs. a ‘full screen’, each has a different aspect ratio. How the aspect ratio differs from the resolution is in that the aspect ratio will tell you the basic shape of the video display, the resolution will be how sharp the picture is. Regular TV displays have an aspect ratio of 4:3 (4 parts wide x 3 parts tall). High definition TV has an aspect ratio of 16:9 (16 parts wide x 9 parts tall). This aspect ratio allows a 25% wider view, so for instance with a mountain panorama you will see 25% more of the mountains.

Most LCD TV’s have a native, or inherent, aspect ratio of 16:9, though some have both 16:9 and 4:3, or strictly 4:3. All this becomes important when you figure in the broadcast signal or video source, which can be sent in a 16:9 or 4:3 format as well. More on this in a minute.

When you look at the resolution specs for an LCD TV, you’ll see numbers such as 1080, 720, or 480. These numbers are the ‘height’ of the display, or more accurately the number of lines across the display. These are standardized, that is they have a corresponding width that determines if they have a 16:9 aspect ratio or a 4:30 aspect ratio.

*‘1080′ and ‘720′ have an aspect ratio of 16:9 (1920 x 1080 and 1280 x 720 respectively)

*‘480′ can be 704 x 480, which can be both 16:9 and 4:3

*‘480′ can also be 640 x 480, which has an aspect ratio of 4:3

Other resolution sizes you’ll see are ‘768′ which can be 1024 x 768 (4:3, also referred to as ‘XGA‘), and  also 1366 x 768 (16:9)
These are a whole lot of numbers , so look at both the resolution spec number AND  the aspect ratio for the LCD TV you’ve got your eye on.

The next thing you’ll see associated with the resolution spec number is either an ‘I’ or a ‘p’. These refer to either ‘interlaced’ or ‘progressive’.

This has to do with how the display lines are ’scanned’, that is each pixel in each line is sent new instructions on which colors and how bright to display. When all the lines in a display are scanned, you’ve got a whole new picture. With interlaced, first even number lines are scanned, then the odd numbered lines, each cycle taking 1/60 of a second, so you’ve got 30 new frames, or pictures, each second. With progressive, all the lines are scanned in 1/60 of a second, so you’ve got 60 new frames each second.

Does this matter? Motion picture film has a frame rate of 24 per second.  720P is virtually identical to 1080i. A 1080p display will cost up to $1,000 more than a 1080i, and the manufacturers will have you believe that this is money well spent. Yet in side by side comparisons there is some perceptible differences between the various resolution and scan types, but in blind comparisons most people can’t identify one type over another, let alone say which one is better.

It might come down to bragging rights. If you shell out the bucks for an 1080p, then you certainly have the right to tell people about it.
Here’s another factor to consider. The highest HDTV resolution that is being broadcast is 1080i and 720p, there are NO plans in the works to transmit 1080p on cable, satellite or broadcast. Blu Ray is the only DVD format in 1080p. Sony PS3 and Xbox 360 both have 1080p games (The PS3 is also a Blu Ray player.)

Unless you plan on collecting Blu Ray DVDs (which has an awesome picture quality, but again isn’t necessarily better than 720p or 1080i. Regular DVDs are almost all 480i, though there are some ‘Progressive DVDS’ at 480p.), or have a PS3 or Xbox 360 with 1080p games, then you would be better off  taking the money you would have spent on a 1080p LCD TV and investing  it in a better home stereo sytem.

As a side note, most DVDs are widescreen (some offer the choice between wide-screen and full-screen), and work best with a 16:9 display.

The next concept to grasp is the ‘contrast ratio’. This is a measure of the difference between how dark and how light the screen can display the blackest black or the whitest white.

This can be a real jungle of facts and figures. Unless you’re dealing with a top-tier manufacturer, most manufactures play games with how to improve their contrast ratio by using dubious testing methods. You’ll see figures from 800:1 all the way up to 1,000,000:1. The higher the figure the more unlikely the reality in real-world viewing conditions (i.e. Your living room.)

This is one of two areas where LCD TVs suffer. They typically do not display blacks near as well as a comparable plasma display. However recent developments by the better manufacturers have made vast improvements in this area. The best way to evaluate the relative quality in contrast ratio for the LCD TV you’re considering is to actually look at the display at a local retailer. Another tactic would be to check out user reviews from people who are familiar with the inherent problem with LCD TVs and see what  they’ve got to say. If you rely on manufacturer specs for this aspect of your new LCD TV, you’re just about aiming blind. However keep in mind that the top-tier manufacturers have gotten this problem resolved to where their displays are very comparable with a similar plasma display.

When you get your new LCD TV home you’ll want to spend the time to correctly set up the contrast to optimize it so you get the best contrast ratio, but do not overtax the backlighting and shorten the lifespan of your investment.

Another very important specification to understand is the ‘response rate’. This refers to how long it takes for the pixels that make up the display screen  to ‘turn off’ from a charged state, ready to be charged again. A poor response rate results in ‘ghosting’,  ‘leading’ or ‘trailing’, all of which are terms for the screen not keeping up with the action, and leaving a blurred, trailing image of a fast moving object. The response rate is measured in milliseconds.  A very fast response rate is 4-6 ms. An average response rate will be less than 20 ms. Anything above this is a poor response rate, and will be very noticeable on the screen. This is another aspect of LCD TV technology that has improved greatly with the top-tier manufacturers. The lower level products will not be so hot.

And one last factor in evaluating an LCD display is the viewing angle. Just like with a computer screen, as you step off to one side with an LCD TV the colors distort and and the blacks turn gray. This is another factor which determines the contrast ratio.
The better displays will have a viewing angle of up to 70 degrees off center, which is very good. Cheaper knock-offs will start to fade at 30 degrees.

Again here, actually looking at the display you want and checking it out for yourself, or relying on intelligent user reviews, is your best bet. Another factor here is to consider where you plan to put your new TV and the size of the display. Are you looking at a fairly large unit to go in a big living room? The viewing angle becomes a more important factor. Is it going in a den or home office where you’ll be watching it mainly from your favorite chair? The viewing angle isn’t that important.

These are the main factors to look at in evaluating an LCD TV- the resolution and aspect ratio, the contrast ratio, response rate and viewing angle. There are many other features offered by different manufacturers, and you’ll want to spend some time checking out which is the best feature set for your needs, but in terms of picture quality, these are the five big ones.

One Response to “lcd televisions”