LCD TVs Brightness And Contrast
by: Eli Aloisi
Unlike computer monitors, brightness is an important parameter in the choice of a LCD TV set. Since a TV set is viewed from a distance, a (measured) brightness of 220 to 250 nits is appropriate, where for a computer monitor, that would be too bright. When we talk about brightness here, we're referring to the values we've measured ourselves, not the exaggerated, basically useless values claimed by the manufacturers. Some claim up to 800 nits of brightness, a level that would be like looking at a welding torch through a color slide.
Contrast is another story. A good contrast level is always preferable, but you have to be careful not to confuse contrast ratio and screen dynamics. Here's an example to make that a little more clear.
Here I am trying to display concentric circles in shades of gray, from the lightest to the darkest. Screen A shows the shades correctly, but screen B shows only two shades. They have the same contrast ratio - that is, the relation between the whitest point on the screen and the blackest - but not the same dynamics. Screen A shows more details and more nuances than screen B. So as you can see, you need to be careful about manufacturers' claims regarding contrast ratio.
Latency is a crucial parameter for users of LCD Televisions, because LCD panels are fundamentally slow. The latency measurement indicates the time it takes for a pixel to change from totally black to saturated white and back to totally black again. Unfortunately, that value is not very representative of reality, because pixels rarely make such extreme transitions. A pixel can change, for example, from dark gray to a lighter gray, and in that case the latency is much worse than what the manufacturers claim.
This curve shows the different latency values as a function of the gray level to be displayed. A change from black to white is shown on the curve as a point at 255 on the X-axis, a black-gray transition is 125 on the X-axis, an alternation between black and dark gray is 50, etc. The official ISO response time specified by the manufacturer is only for black/white transitions (0/255). While the value we measured is in agreement with the manufacturer on this point, it doesn't mean much as far as the panel's real-world responsiveness is concerned.
While computer applications are highly sensitive to latency, TV sets are a different matter. A TV doesn't have a refresh rate of 60Hz by default - depending on the format, the rate is most often 30 Hz, or 30 images per second interlaced. That would seem to mean that a latency of 33 ms (1/30 Hz) would be sufficient, but that's not so. It's theoretically sufficient for an interlaced signal, but not for applications on a PC, like video games for example. And with PC/TV convergence the coming thing, 33 ms is not really enough. It would also rule out progressive video formats like 720P. And even for ordinary TV use, a 33 ms latency would be visible when sudden movements occur on-screen.
About The Author
Eli Aloisi is one of the many knowledgable staff members that encompass the PlexHomeTheater.com community. For more great articles check out www.PlexHomeTheater.com.
|
Plasma TV for the Home Theater
Plasma TV for the Home Theater
by: Tom Ace
One of the hottest topics in home entertainment is home theater. And one of the hottest topics in home theater is plasma TV.
Plasma TV for your home theater is actually only a receiver, much like your computer monitor, and is only one component of a great home theater. Still, it's an arguable point that the plasma TV is the part of the home theater package that you'll be viewing and is therefore a very important component.
Consider the technology of the plasma TV and you'll understand why this is such a great choice for the home theater. Typically, a plasma TV is a flat screen monitor. Because of the thin design, it becomes very versatile in the home theater design. Remember the television sets of a few decades ago? They were bulky pieces of furniture and the rest of the room was often arranged around the television set. A plasma TV, by comparison, is easier to manipulate. Most models will even...
Plasma TV for the Home Theater
Televisions > Plasma TV for the Home Theater
UK Broadband
UK Broadband
by: Neil Shevlin
Ever since August 2000 when BT first launched their broadband internet package, speeds have been increasing and prices have been dropping. The end aim of the UK government and all broadband providers is high-speed internet in every home in Britain.
Broadband is the name given to always-on, high-speed internet. High-speed internet is a connection that runs at 512Kbps or faster. Currently 6 million homes in the UK have a broadband connection, either through ADSL, Cable or LLU, of which 4 million are connected by ADSL.
The fastest commercially available internet connection out there is 8Mbps. With such a fast speed users can download music in seconds, stream live television and be shared between a household of computers so all the family can have a decent internet connection.
Wanadoo Broadband, the main competitor to BT broadband is running a LLU trial over summer 2005. Local Loop Unbundling is currently...
UK Broadband
Televisions > UK Broadband
How To Choose The Snowboard That?s Right For You
How To Choose The Snowboard That?s Right For You
by: Danielle Rose
Picking out a snowboard can be difficult because there are so many brands and types to choose from. Three major types of boards are freestyle, alpine, and freeride. When picking out a snowboard, you need to determine what style of riding you are going to be doing, and get a board specific to that type of riding. If you are going to be spending your time in the half-pipe a freestyle board is best...
LCD TVs Brightness And Contrast
Televisions > How To Choose The Snowboard That?s Right For You
LCD TVs Brightness And Contrast hearing aids
Are You Thinking Of Buying A Used Car?
Are You Thinking Of Buying A Used Car?
by: Gregory Ashton
Buying a used car can either be a wise or a foolish move. Someone with no background or knowledge whatsoever on finding a good buy might just be duped into a bad deal and end up with somebody else's garbage. But for the knowledgeable buyer, a significant amount of money might be saved by settling with a secondhand car.
Here are some tips to set you on the right track.
1. CONSIDER THE KIND OF...
LCD TVs Brightness And Contrast Are You Thinking Of Buying A Used Car? toyo tires Televisions
Televisions > Are You Thinking Of Buying A Used Car?
Televisions
This page loaded in 0.06059 seconds.