LED LCD without local dimming - AVS Forum
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Old 10-15-2009, 06:33 AM - Thread Starter
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Hello,

I'm very new to televisions here so I apologize if I'm posting in the wrong area or asking a seeminly-stupid question.
I'm about to buy my first real TV this holiday season. I've been doing some research and have gathered that the new LED LCD tvs are very highly recommended.
However, I've read about some LED LCD tvs that DO NOT have local dimming. I'm confused: I thought the purpose of LED is so that it can "turn off" individual LEDs and create those highly desired true black colors. What is the purpose of a LED LCD that does NOT have local dimming then?

Thanks for any input.
-Fred
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Old 10-15-2009, 06:52 AM
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They use LED lights around the edge of some models(not locally dimmed) to provide the backlight which allows for a thinner, more aesthetically pleasing TV. I'm certainly not a pro on the subject but that's my take.
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Old 10-15-2009, 06:56 AM
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Quote:
Originally Posted by FREDSMITH View Post

Hello,

I'm very new to televisions here so I apologize if I'm posting in the wrong area or asking a seeminly-stupid question.
I'm about to buy my first real TV this holiday season. I've been doing some research and have gathered that the new LED LCD tvs are very highly recommended.
However, I've read about some LED LCD tvs that DO NOT have local dimming. I'm confused: I thought the purpose of LED is so that it can "turn off" individual LEDs and create those highly desired true black colors. What is the purpose of a LED LCD that does NOT have local dimming then?

Thanks for any input.
-Fred


So companies like Samsung can market their edge lit led tv's and rip people off that do not know what you have discovered.

Now led tv's that are Back lit usually have local dmming and better blacks. But they are not slim like the edge lit models.

Most consumers assume that an led tv has to be ultra slim or it is not the best. So they pay out thousands for a tv that is way overpriced.
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Old 10-15-2009, 03:47 PM - Thread Starter
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Alright, so again ... forgive me .. I'm an ULTRA-novice to the hi-tech visual world (I've been audio exclusive for years.)

When it says "edge-lit" ... what exactly does that mean? The actual EDGE of the monitor? I can't find (via google) a good description/photo of what edge-lit means.

I'm gathering from those 2 comments/responses that a LED LCD without local dimming essentially is a crock? Is that a good assessment?

Thanks again.
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Old 10-15-2009, 04:33 PM
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Edge lit LED LCD displays are better in contrast then the standard floursant light back lit LCDs. However local dimming LED LCD displays are even better but cost more.

Following is a Bing search on them:

http://www.bing.com/search?q=edge+li...&filt=all&qs=n
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Old 10-15-2009, 04:52 PM
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Fred you have 2 types of LED TV's. Edge-Lit & Back-Lit.

Edge-Lit means the LED's are around the border of the TV & they don't do Local-Dimming.

Back-Lit means the LED's are all over the TV & they do Locally Dim.

There are 5 companies right now offering LED TV's

SAMSUNG (Edge-Lit & Back-Lit/Local Dimming)
LG (Back-Lit/Local Dimming)
TOSHIBA (Back-Lit/Local Dimming)
VIZIO (Back-Lit/Local Dimming)
SHARP (Back-Lit No Local Dimming)

Here are 2 links that should be helpful

http://reviews.cnet.com/8301-18438_7...rColumnArea1.2

http://reviews.cnet.com/4321-6482_7-...rColumnArea1.2
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Old 10-15-2009, 05:34 PM
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Quote:
Originally Posted by FREDSMITH View Post

Alright, so again ... forgive me .. I'm an ULTRA-novice to the hi-tech visual world (I've been audio exclusive for years.)

When it says "edge-lit" ... what exactly does that mean? The actual EDGE of the monitor? I can't find (via google) a good description/photo of what edge-lit means.

I'm gathering from those 2 comments/responses that a LED LCD without local dimming essentially is a crock? Is that a good assessment?

Thanks again.

Well you be the judge of the picture quality. I just think marketing an LCD tv with edge LEDs as the backlight calling it an LED tv is very misleading. I do like the picture quality of some of the edge lit led tv's, but no more than the high end ccfl lit sets. Now backlit led tv's are generally a better picture.

Regaurdless of your preference they are all LCD tv's.
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Old 10-15-2009, 05:40 PM
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Quote:
Originally Posted by BFJ 96 View Post

Fred you have 2 types of LED TV's. Edge-Lit & Back-Lit.

Edge-Lit means the LED's are around the border of the TV & they don't do Local-Dimming.

Back-Lit means the LED's are all over the TV & they do Locally Dim.

There are 5 companies right now offering LED TV's

SAMSUNG (Edge-Lit & Back-Lit/Local Dimming)
LG (Back-Lit/Local Dimming)
TOSHIBA (Back-Lit/Local Dimming)
VIZIO (Back-Lit/Local Dimming)
SHARP (Back-Lit No Local Dimming)

Here are 2 links that should be helpful

http://reviews.cnet.com/8301-18438_7...rColumnArea1.2

http://reviews.cnet.com/4321-6482_7-...rColumnArea1.2


Sony has the xbr8 and xbr10 led LCD tv's.
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Old 10-15-2009, 06:16 PM
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Quote:
Originally Posted by chdwil View Post

So companies like Samsung can market their edge lit led tv's and rip people off that do not know what you have discovered.

Now led tv's that are Back lit usually have local dmming and better blacks. But they are not slim like the edge lit models.

Most consumers assume that an led tv has to be ultra slim or it is not the best. So they pay out thousands for a tv that is way overpriced.

Rip them off? People should learn about the technology before they buy.
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Old 10-15-2009, 06:46 PM
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Originally Posted by omeletpants View Post

Rip them off? People should learn about the technology before they buy.

I agree. And give the OP credit for doing a little homework before the purchase. If more consumers asked questions the product would be better and more competively priced.
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Old 10-16-2009, 03:08 AM
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Quote:
Originally Posted by FREDSMITH View Post

I'm gathering from those 2 comments/responses that a LED LCD without local dimming essentially is a crock? Is that a good assessment?

Thanks again.

not really....

there are TV's with full array led backlight system that do not have local dimming, but utilise excellent LCD panel technology to achieve exemplary sharpness. These panels will be used in upcoming Pioneer TVC's...

The main reason LED's are used is to overcome blue push... inherent problem with CCFL backlight systems.

Boky
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Old 10-16-2009, 06:32 AM - Thread Starter
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Thank you for all of the valuable input. I am going out to the store this weekend to "test drive" a bunch of tvs. As I said before, it's going to be a Christmastime purchase, so I'm just getting my homework in 2 months prior.

I'm not overly concerned with how thin the set is, though I will be most likely mounting it on a wall at eye-level.

If I have questions from what I see this weekend, I'll post them here.

Again, thank you for all the input/help!
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Old 10-16-2009, 08:16 AM
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Quote:
Originally Posted by chdwil View Post

Sony has the xbr8 and xbr10 led LCD tv's.

You are correct. My bad
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Old 10-16-2009, 09:24 AM
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Quote:
Originally Posted by Extreme_Boky View Post

...These panels will be used in upcoming Pioneer TVC's...

This is interesting. Do you have any further references to these new sets?
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Old 10-16-2009, 01:24 PM
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Originally Posted by davegow View Post

This is interesting. Do you have any further references to these new sets?

I've been hearing rumours from many sources....even retail shops...

http://www.smarthouse.com.au/TVs_And...ustry/N2T2C4G2

Boky
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Old 10-16-2009, 01:40 PM
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I don't think that your almost one year and an half old link is at all revelent since AFAIK Pioneer is no longer manufacturing the TVs that they are selling under their brand name.
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Old 10-16-2009, 02:07 PM
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That article is dated. HARD

- Chip
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Old 10-16-2009, 09:37 PM
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Quote:
Originally Posted by walford View Post

I don't think that your almost one year and an half old link is at all revelent since AFAIK Pioneer is no longer manufacturing the TVs that they are selling under their brand name.

rumours from 2 most reputable retail chains in Australia is that Pioneer has teemed with Sharp to utilise Sharp LCD panel technology... my nephew works in one, and very good friend in second shop this is a result of a joint venture that started in 2007...they are hoping to capitalise on Kuro advanced processing technology and Sharp advanced LCD panel manufacturing.

1 min web search.

http://www.hometheatershack.com/foru...upply-lcd.html


Boky
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Old 10-16-2009, 10:14 PM
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Quote:
Originally Posted by chdwil View Post

I just think marketing an LCD tv with edge LEDs as the backlight calling it an LED tv is very misleading.

I agree. Actually, I think marketing any LCD TV as an LED TV is misleading, when the main display device is an LCD. When they get a 1920x1080 array of LEDs creating the image, then I'll go for it.

Michael
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Old 10-17-2009, 12:30 AM
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I took a look at a Samsung LED LCD at sears the other day, no way it was a local dimming machine but it looked incredible.

Would it be a safe statement to say the non locally dimming (edge lit) LED LCD's produce a better picture than a standard LCD TV? If the answer to that is no, why would someone buy an edge lit over a standard LCD which is significantly cheaper. Other than the thin factor.
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Old 10-17-2009, 01:28 AM
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Let’s put local dimming aside for the moment. The only advantage to local dimming is to increase contrast ratio of the display device. LED backlights can be turned on and off more quickly than fluorescent lamps. This means that the backlight source can be turned off during the LED lag time when they transition from the twisted state to the “un-twisted’ state (known as the response time). This helps to reduce the “smear” effect. 120HZ and 240HZ refresh rates of the TCON circuits also helps reduce the smear rate and a backlight source that strobes in unison with the refresh rate helps to minimize this effect. The net result is smoother video flow and increased contrast ratio.


Whether the panel is edge-lit or backlit by the LED’s is minimal in this argument. They both perform the same functions as described above. Either backlight method is spread out by diffuser methods so as to provide even backlighting as best as possible.

Those who think they know everything annoy those of us who do.
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Old 10-17-2009, 10:14 AM
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Display veteran,
Bassed on your extensive testing do you agree with the following editor's post that there are LED units with local dimming that is different by zones and local dimming that is the same for all zones?

http://reviews.cnet.com/4321-6482_7-6661380.html
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Old 10-17-2009, 10:50 AM
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Current local-dimming sets lead edge-lit sets by a fairly wide margin in black level, peak brightness, and uniformity. Uniformity is especially bad. And while edge-lit sets lead CCFL in color temp, color gamut doesn't look nearly as good. You solve one or two problems, while creating a whole host of other problems.

IMO, It's easy to get transfixed by a ultra-thin television with eye-popping vibrant colors. While I still rather take a well-made CCFL over a poorly implemented LED set.
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