hello, I've been reading a lot but am still confused as usual:
I'm looking at a LCD in a store and the specifics are like 500 cd/m2 and 16 ms Response Time. These stats kinda remind me of the LCD monitor for my computer I have at home, so is there a similarity between LCD TV and the one we use for computer purposes? Does the 500 cd/m2 and response time a big issue?
And with the contrast ratio, I see a plasma with 5000:1 contrast ratio so is that a real big difference with a LCD monitor with 1000:1.
I'm thinking of getting a LCD TV since i've been hearing so many troubles with owning a plasma TV but is LCD TV a bigger set back then a plasma TV?
THX
RandyM
Unregistered guest
Posted on
Joe, it's good that you are asking these questions before making such a big investment. It really comes down to how you will use the display and what characteristics are most important to you.
Yes, there are some similarities between LCD TV and LCDs for computer, but mostly a good quality panel is key to the quality. Response time is important for fast action. If the panel has a slower response time(>16ms), you may see smearing or pixelation as the panel races to update during fast action. If this would bother you, take it into account. Light output is another key characteristic. 500 cd/m2 is a nice bright display. . in fact, it's on the order of larger 50" DLP displays. So, if you enjoy the "pop" of a bright picture, look at the sets on display and make sure you choose a bright one. Also, a plasma is capable of very bright peak light output in small areas of the screen, but when a full field white picture comes up, the plasma suffers from light output limiting, much like a CRT, and is dim compared to LCD. LCD, because the backlight is constant behind the panel, has equal peak whites regardless of how much white is on the screen.
Contrast ratio can be measured so many ways that I have found most manufacturers have printed numbers that can not be compared. I compare it to bragging at the urinal. Some of the best plasmas may have contrast ratios in the several thousand to 1, but so do DLPs, so they really need to be compared side-by-side. LCDs have lower contrast ratio because of the technolog involved. The LCD panel is blocking light as well as it can on dark scenes, but some light stills get through, making the blacks somewhat gray, which reduces contrast ratio to 1000:1 or less. If you're watching an LCD in a bright room, you might not find the difference objectionable. If not, plasma has the advantage.
Lastly, plasma gases are consumed and loose light output, likely going to 1/2 of new light output in 5-6 years. And if you any do any gaming, fixed patterns will eventually cause uneven consumption of the gases and "burn" the screen. If that's important to you, consider that LCD backlights last 40K hours or more and LCDs can't be burned because the panels are only blocking light.
1. Time to half brightness- Plasmas are rated between 30,000 and 100,000 hours. Just do the math. Also, when you calibrate a plasma, the brightness/picture control winds up going way down, depending upon the adjustment. Most plasmas will be replaced long before half-brightness occurs. And at least they in genral wear evenly ( the phosphors in the pixels.)
2. LCD " Burn In"- Flat LCDs have several flourescent bulbs behind them, not just a single backlight ( LCD Projection Monitors have this- different than LCD flat screen). Over time, LCD bulbs tend to dim unevenly, this is reproted by many owners over the net. This uneveness is the LCD form of burn in.
3. Response time- LCD flat screens have improved over time, yet their response times, or refresh rates, are still slower than a plasma and therefore blurring during, lets say, sports, is often discernible.
4. Contrast Ratios- There is no universal formula that all manufacturers agree to use, so when you see 10:000 to 1- its kinda like " Um Ok". However, you can count on the numbers with in the same brand for comparison. That being said, there is a very real difference between contrast ratios in LCD flat screens, which are lower, and Plasmas, which tend to be higher. This is the single most important determinant in Picture Quality, particularly in darker rooms. The reason is that our eyes can perceive differences in contrast ratio at, lets say, 8 feet much better than we can perceieve differences in pixel counts. AS a result, LCD flat screens lose shadow detail, or the ability to see detail in dark scenes, much more than most plasmas. So a movie like Sin City, fairly dark, is, to me, a problem in a dark room on an LCD flat screen. In a bright room however, LCDs have an eye catching brightness while a Plasma can look more dull- this is particularly evident in stire set uops like Best Buy, where often times, The lights are fairly bright, and much more so than in home viewing.
My opnion, having gone to CES last year and going again in January, so seeing the latest side by side, is that LCD flats have made great strides in a scant few years in catching up and improving some of their weaknesses. But when I see an LCD, I know I am watching a TV. When I watch a plasma, its a much more realistic experience, like looking through a window.
BTW- You have two very good replies on your question. I thought Randy made good points.
RandyM
Unregistered guest
Posted on
I agree with everything with you say, Marc. I, too, am an insider to the business, so we see a lot of things that most consumers making a decision do not have the chance to observe.
I believe in Sharp TVs the backlight can be replaced. I don't know if it is true. So if you are able to replace the backlight, can you increase the longivity of the TV?
My answer is yes. Assuming the replacing of these things is really doable. I havent ever done that myself.
Marc
Will McK
Unregistered guest
Posted on
Building off of the refresh rate issue, how discernable is the difference between a 16ms refresh rate and an 8ms refresh rate, both in LCD TVs?
Also, have you heard of any problems coming from using a DVI-D connection with the LCD display? I originally had my cable receiver (Motorola DCT-6412) connected to my TV via component cables. I purchased a DVI-D cable today and when I connected it, the picture it provided had a line of flickering light along the top. Assuming it was a signal issue, I looked up the Motorola manual for the cable box, and changed the output. However, the only method that would eliminate the flickering line along the top of the display was to set the Motorola output at 1080i. I would think a 32" LCD tv would have a native resolution of 720p, so is this ultimately causing my signal to be worse? I think this because the TV then has to down-convert the cable signal and display it in the number of lines it actually has.
Am I wrong to assume these things? Or could it possibly be a problem with the DVI-D cable?
RandyM
Unregistered guest
Posted on
There are a number of things at play here. It sounds like you are seeing the VBI info on line 21 or edge of raster. Many HD feeds that are upconverting analog signals are not even bothering with removing the VBI info. . . ESPN on DirecTV, for example, does this all the time. You may have a vertical centering issue when you connect the DVD-D cable. Check your tv to see if you can adjust geometry to remove the line at the top. Secondly, many tvs assume a computer input with DVD-D or HDMI, so they reduce the overscan in that mode to 0%. . . makes sense, they don't want to cut off scroll bars, but it's a bad choice for television material. You may be right about the 720p native resolution. . . it will vary by panel. I doubt you have a problem with your cable.
A refresh rate of 16ms is ok, but 8ms is great. You will notice a difference in fast action, sports, for example. . . the amount of difference depends how picky you are about picture quality.