Now that the usual suspects have caused the 81 series thread to be closed I don't know where to post this :)

When viewing the 81 series vs other LCDs and Plasmas I could definitely see some severe black crush and loss of detail in dark areas as well as some cross-talk on certain dark scenes. I though about it and it seems logical that this would be an inherent problem with dimming technology as the diffuser between the LEDs and pixels tends to spread the light out laterally causing cross-talk between bright and dark areas. I guess this is also why the dynamic contrast can be high but the static contrast is not so high. And the black crush is due to the local dimming LED block size limitation I guess.

A way to solve this is to use a pixel compensation circuit that adjusts the voltage on the liquid crystals to emit more light in areas with BLD induced black crush. Here is a picture of the results. In theory this could also help with cross-talk as the pixels affected can be adjusted to emit slightly less light.

http://i222.photobucket.com/albums/dd126/xrox/Localdimming.jpg

(a) - LED backlight without local dimming
(b) - LED backlight with local dimming
(c) - LED backlight with local dimming and pixel compensation

While obviously not perfect (still detail loss) it is much better with pixel compensation.

So my question is does the Samsung 81 series use pixel compensation or is the black crush and halos I'm seeing due to the inherent problems with local dimming?

So my question is does the Samsung 81 series use pixel compensation or is the black crush and halos I'm seeing due to the inherent problems with local dimming?

All recent Samsung LCDs have inaccurate gamma that crushes shadow detail. It has nothing to do with local dimming. You probably should know that it's not very wise to judge local dimming as technology based on one product. :rolleyes:

All recent Samsung LCDs have inaccurate gamma that crushes shadow detail. It has nothing to do with local dimming. That in no way answers my question :rolleyes: Does the 81 series have pixel compensation? If it does than yes maybe some of the black crush is caused by poor gamma. If it doesn't than black crush and cross talk are inevitable. Care to explain how local dimming does not cause black crush and cross-talk in its basic form?

You probably should know that it's not very wise to judge local dimming as technology based on one product. :rolleyes: You seem to do just that......

http://i18.tinypic.com/81j8bdj.jpg

The area lit by each LED is much larger than pixel size, so small bright objects cannot be illuminated correctly with a darker background.Thanks OreoJoe, that picture is also a great representation of the cross-talk problem as well. The large LEDs just enhance the problem.

A sopisticated pixel control circuit can reduce the effects significantly though. I can't seem to find a reference to the 81 series using one however. Hopefully newer products will implement this feature.

Does the 81 series have pixel compensation? If it does than yes maybe some of the black crush is caused by poor gamma. If it doesn't than black crush and cross talk are inevitable.

81 seems to apply some form of gamma correction to each zone. There's a white paper from Samsung that discusses local dimming algorithms, but no one knows that what kind of algorithm 81 is using. According to HDTVtest (http://www.hdtvtest.co.uk/Samsung-LE52F96BD/Calibration.php)review black crush is mostly avoidable:

"Use the wrong settings and/ or patterns and you may end up clipping shadow detail/ highlights resulting in an S- shaped gamma curve rather than a more desirable exponential one"

Care to explain how local dimming does not cause black crush and cross-talk in its basic form?

Well the possibility and amount of crush/light leakage is always content/implementation dependant, don't you think? There's also limitation what human eye can see. A display designed with human eye limitations in mind would have ideally 150:1 pixel to pixel contrast. A local dimming display with 5000:1 static panel from AUO would require under 2000 dimming zones.

81 seems to apply some form of gamma correction to each zone. I'm not talking about gamma of the LC or zones. I asked if the 81 series does pixel compensation and it seems it does not. Therefore the cross-talk and black crush I observed on dark scences is inevetibley caused by local dimming.

Well the possibility and amount of crush/light leakage is always content/implementation dependant, don't you think? There's also limitation what human eye can see. A display designed with human eye limitations in mind would have ideally 150:1 pixel to pixel contrast. A local dimming display with 5000:1 static panel from AUO would require under 2000 dimming zones.What does that have to do with pixel compensation? Sorry but even if you didn't dodge questions like this I wouldn't believe anything you say as your reputation and credibility here are at an all time low.

And why so defensive? New LED dimming models will hopefully have pixel compensation which greatly improves the issue (but not solve it).

Well "pixel compensation" is gamma correction. You can't magically pass more light through lcd panel of certain spec. :rolleyes:?? No it isn't. Pixel compensation is local adjustment of LC voltage to compensate for cross-talk and black crush based on distance and brightness of active LED zones.

?? No it isn't. Pixel compensation is local adjustment of LC voltage to compensate for cross-talk and black crush based on distance and brightness of active LED zones.

You are talking about gamma correction again.

What does that have to do with pixel compensation?

I just gave you an example of dimming zone requirements for perfect hdr display without any possibility of noticeable black crush. Since you have mixed gamma correction with your own term "pixel compensation", this thread is completely useless.

A way to solve this is to use a pixel compensation circuit that adjusts the voltage on the liquid crystals to emit more light in areas with BLD induced black crush.

Liquid crystals don't emit any light. Are we talking about LCDs or not?

Now that the usual suspects have caused the 81 series thread to be closed I don't know where to post this :)



the thread is reopened with a warning to the 'usual suspects'

You are talking about gamma correction again. Completely wrong....again :). You might want to look that one up.....

I just gave you an example of dimming zone requirements for perfect hdr display without any possibility of noticeable black crush. Since you have mixed gamma correction with your own term "pixel compensation", this thread is completely useless. I don't think you know what you are talking about. Do you know why LED-HDR works? And if this thread is completely useless than why is the problem being researched extensively? Maybe if you think it is useless you shouldn't read or post here anymore.

mixed gamma correction with your own term "pixel compensation"LOL , "pixel-compensation" is a Samsung term specific for LED-LCD. The photos I posted are from Samsung :)

Liquid crystals don't emit any light. Are we talking about LCDs or not?I was referring to transmission of light. The voltage controls the orientation of the LC which controls the amount of light transmission through the cell. Pixel compensation is local control of the LC voltage to compensate for local problems with LED backlight cross-talk and black crush.

You might want to look that one up.

Care to explain how you can increase the native contrast of LCD panel by using "pixel compensation"? It's still gamma correction if native contrast isn't increased.

[mod inappropriate comments removed]

Care to explain how you can increase the native contrast of LCD panel by using "pixel compensation"? It's still gamma correction if native contrast isn't increased.By locally controlling voltage on the LC cells you can literally hide the LED cross-talk effect and also locally increase transmission to reduce black crush. Samsung claims an increase in static contrast on certain scene types upwards of 20,000:1.

By locally controlling voltage on the LC cells you can literally hide the LED cross-talk effect and also locally increase transmission to reduce black crush. Samsung claims an increase in static contrast on certain scene types upwards of 20,000:1.

Have they increased the panel contrast to 20000:1 or are we talking about LED*LCD contrast? It's gamma correction if we are talking about latter.

flatline can't stand any threads that go to the heart of LCDs inherent weaknesses!

Xrox is totaly right--just because the 81 hasn't solved LED dimming problems doesn't mean that they might not be solved in the future.

Xrox is totaly right--just because the 81 hasn't solved LED dimming problems doesn't mean that they might not be solved in the future.

Well the problem is that samsung 81 is already using gamma correction on each local dimming zone. The only solution is combination of better panel, more dimming zones and better algorithms, if you are looking for the perfect display.

Well the problem is that samsung 81 is already using gamma correction on each local dimming zone. The only solution is combination of better panel, more dimming zones and better algorithms, if you are looking for the perfect display.Nope. Your still not on the same page as this thread. Please read the first post again. This is Samsung's data.

Pixel compensation is a neat trick in itself but does not completely solve the LED problems. Since it doesn't seem the 81 series uses PC, I wonder when or if Samsung will be incorporating this into a product?

I know this may be slightly off topic xrox, but what is the difference between how Samsung's LED local dimming works and how Dolby Contrast or Dolby Vision is supposed to work. Do you think that incorporating Dolby Contrast into one of these panels may provide part of the solution to the problem you are discussing?

interesting (but I don't think Dolby has any customers for it yet)

Dolby Contrast or Dolby Vision (avsforum.com/avs-vb/showthread.php?p=12357534)

I know this may be slightly off topic xrox, but what is the difference between how Samsung's LED local dimming works and how Dolby Contrast or Dolby Vision is supposed to work. Do you think that incorporating Dolby Contrast into one of these panels may provide part of the solution to the problem you are discussing?From what I've read the main difference is that the dolby systems calculate the effect of the neighboring LED on the diffuser plate optics. In other words they compensate for known cross-talk by reducing the brightness of the LEDs at high contrast transitions of an image, essentially using the cross-talk to their advantage. It is difficult to explain but I may be able to show an image of this in action.

Also, Dolby contrast does not use pixel compensation but Dolby vision does.

Also, Dolby contrast does not use pixel compensation but Dolby vision does.
How do you know that?

How do you know that?It says so on dolby's website.

It says so on dolby's website.
It says nothing about only Dolby Vision having pixel compensation. The reason why this technology is superior is that it implements the algorithm that drives both LED matrix and LC panel in a way as to minimize backlight blur. If Dolby Contrast only controlled LED matrix, there would be no reason to license the technology as other manufacturers seem to have figured out how to do this already.

The difference between Contrast and Vision does not lie in a way in which LC panel is driven.

It says nothing about only Dolby Vision having pixel compensation. .From Dolby wesbsite: Dolby Vision completely addresses LCD limitations by taking local backlight dimming to its ultimate level—modulation of each individual LED in the backlight. Dolby Vision uses a backlight of carefully spaced LEDs. The proprietary Dolby technology “reads” each screen image and calculates the backlight drive level for each LED individually, based on the intended contrast of the image. It then creates the image with the LEDs, controlling each LED so that it not only maps to the image but to the neighboring LEDs, producing a smooth transition. In addition, Dolby Vision performs LCD compensation based on the LED backlight. While being every so vague the details can be found in brightsides SID papers. It is not clear if they are performing global or local pixel compensation.

The reason why this technology is superior is that it implements the algorithm that drives both LED matrix and LC panel in a way as to minimize backlight blur. If Dolby Contrast only controlled LED matrix, there would be no reason to license the technology as other manufacturers seem to have figured out how to do this already.

The difference between Contrast and Vision does not lie in a way in which LC panel is driven.Well I can only comment on what I read and the technical papers suggest the difference between Dolby algorithm's and Samsung is that Samsung does not take into account the diffuser plate optics while Dolby does. Essentially Dolby is using the cross-talk to illuminate parts of the picture.

You should post this stuff on your Dolby thread. Here is some more on Dolby contrast:

The Dolby® Contrast proprietary technology broadly addresses LCD limitations by replacing globally controlled backlights with locally controlled backlights. This enables the modulation of each individual LED, or clusters of LEDs, in a backlight, thus significantly improving both static and dynamic contrast.

Dolby Contrast technology uses a backlight of optimally positioned LEDs. The proprietary Dolby technology first analyzes a standard 8-bit video frame to match the higher contrast levels that a local dimming backlight can attain. Then each video image frame is analyzed and the backlight drive level for each LED is calculated. For each frame, an image is created with the LEDs, accounting for the influence of neighboring LEDs and a display's optical characteristics.

From what I've read Samsung's LED local dimming is identical except they do not take into account the optical diffuser (the cause of cross-talk). And from the descriptions of Dolby Contrast vs Dolby Vision the only difference I see is the compensation?

If there is more then I would love to read about it.

Cheers

http://i222.photobucket.com/albums/dd126/xrox/pixelcompensation.jpg

I would say that all local dimming algorithms perform some kind of LC correction. But that doesn't mean that all of these algorithms are created equal just like some AV codecs aren't. Additionally, other things such as panel contrast, number of clusters, type of LEDs, LED bit-depth also influence the performance.

While sets with D.Contrast and D.Vision can potentially have IMLED backlights, meaning, black levels on both will be the same, the main difference between these two flavors is that the sets with D.Vision will be much brighter. In other words, Dolby Vision does true HDR.

Hmm does that mean 81 uses compensation? I believe so, as LCDs have been using global dimming w/ pixel compensation for a long time - i don't think the 81 could do what it does without it. The crosstalk and crush are from the low density LED matrix samsung used (8x8 or something). Pixel compensation can only go so far to help that misfortune.

Hmm does that mean 81 uses compensation? I believe so, as LCDs have been using global dimming w/ pixel compensation for a long time - i don't think the 81 could do what it does without it. The crosstalk and crush are from the low density LED matrix samsung used (8x8 or something). Pixel compensation can only go so far to help that misfortune.That was my original question. And as of now the answer is no it does not. Possibly next gen though.

Global dimming and global pixel compensation are not the same.......

As for low LED density, it has nothing to do with crosstalk. Crosstalk is cause by the diffuser plate. It means light is spread laterally beyond the LED zone by the diffuser plate. Black crush is caused by low density LED and can be improved by using pixel compensation but not solved.

November 29, 2007 01:45 PM Eastern Time
Samsung’s Super-Clear, LED-backlit Panels Now Featured in Premium LCD TVs


SAN JOSE, Calif.--(BUSINESS WIRE)--New LED-backlit LCD displays of Samsung Electronics Co., Ltd., the world’s largest provider of thin-film transistor, liquid crystal display (TFT-LCD) panels, are now available in large premium-model, full-HD TVs at major U.S retailers for the holiday season. The new panels enable a huge jump in the dynamic contrast ratio from between 5,000:1 and 25,000:1, to 100,000:1 and even 500,000:1, for the clearest images on the market today.
Available in 40-inch, 46-inch, 52-inch and 57-inch diagonal screen sizes, Samsung’s new “local dimming,” LED (light-emitting diode) technology provides a brightness level of 450nits, and reduces power consumption by as much as 30 percent.
“Increasingly, consumers are craving the theatre movie experience at home and local dimming LED backlighting is a highly innovative and energy-efficient way to achieve theatre-like TV picture clarity,” said Scott Birnbaum, vice president, Samsung LCD Business.
Depending upon the number of LEDs used in a screen panel design, the dynamic contrast ratio can improve the contrast in colors by as much as a thousand percent over the CCFL (cold cathode fluorescent lamp) LCD TVs typically used today.
Another significant advantage to Samsung’s “local dimming” technology is that the LED scanning process shuts off the diodes in precise sequences, thereby essentially eliminating any remnants of ‘image ghosting’ that had previously been a drawback in some LCD TVs.
With local-dimming LEDs, hundreds of wafer-thin diodes about the width of the eye’s pupil are electronically turned off and on in exacting sequences that respond to movement on the screen – areas only a fraction of what was previously possible with the most prevalent form of TV backlighting – long, thin fluorescent lamps. In black areas of the picture, the diodes can be completely shut off in order to generate total blackness.
Samsung said that its new extreme-contrast LCD panels is now available in Samsung TVs in the U.S., and also will be featured in HDTV’s produced by other manufacturers.
The local dimming LED display does not contain mercury.

Greenland, none of that addresses the LED issues of black crush and crosstalk which is why this thread was started.

The new panels enable a huge jump in the dynamic contrast ratio from between 5,000:1 and 25,000:1, to 100,000:1 and even 500,000:1, for the clearest images on the market today. The only way to achieve those numbers is using a completely black screen versus completely white screen (dynamic range). However, once a few LED zones activate the diffuser plate spreads the light out causing the static contrast to drop significantly.

....completely shut off in order to generate total blackness. Again, the only way to accomplish this is to turn them all off. When any signal is on the screen the crosstalk and black crush can become apparent.

Here is some news on improving cross-talk:
http://eetimes.eu/semi/202403697

Greenland, none of that addresses the LED issues of black crush and crosstalk which is why this thread was started.

The only way to achieve those numbers is using a completely black screen versus completely white screen (dynamic range). However, once a few LED zones activate the diffuser plate spreads the light out causing the static contrast to drop significantly.

Again, the only way to accomplish this is to turn them all off. When any signal is on the screen the crosstalk and black crush can become apparent.

Here is some news on improving cross-talk:
http://eetimes.eu/semi/202403697

I agree with you. I just posted the Samsung news release to show that they are not claiming anything other than they achieve the contrast figures by shutting off the LED LD backlighting. HDguru and other reviewers have mention the floating blacks, or black crush issues with this first gen. display.

It still is a huge step in the right direction.
It is my understanding that Samsung uses White LED in the 81 series. Have you found any details about what might be soon accomplished by companies using RGB LED LD technology in their panels?

After reading some more it is becoming clearer on what is exactly going on with certain algorithms.

Local dimming
- each LED zone is dimmed according to picture data (the typical LED dimming we know)
- greatly improves contrast by dimming LED zones in dark areas. Problem is that detail is lost in those areas (black crush). Also, it makes lateral bleeding/blooming/crosstalk very apparent from bright areas adjacent to dark areas.

Local pixel compensation
- The dimmed backlight from the local dimming step is sampled to give a luminence profile of the backlight on the diffuser plate. The light spread of each LED is estimated and included in the profile.
- Then the voltage on the LCD pixels is locally compensated to increase light transmission in black crushed areas. It can also reduce light transmission in crosstalk areas if the voltage is not zero to begin with.

Global dimming
- aims to reduce lateral crosstalk by dimming the brightest LED zones. It does this by adjusting the histogram. This reduces the amount of light transmitted laterally on the diffuser plate. Problem is that it causes a large decrease in image brightness.

Global pixel compensation
- attempt to counteract the negative effects of global dimming by opening up the LC cells more to compensate for brightness loss.

Samsung is planning on implementing all 4 algorithms together in one package.

What NXP and I think Dolby are doing is "Local LED compensation". This works by increasing or deacreasing the individual LEDs to compensate for crosstalk. You can see this in the following graphic from NXT. I've also included a graphic from Samsung on global pixel compensation.

http://i222.photobucket.com/albums/dd126/xrox/LEDandglobalLCDcompensation.jpg

It is my understanding that Samsung uses White LED in the 81 series. Have you found any details about what might be soon accomplished by companies using RGB LED LD technology in their panels?I haven't gotten to the RGB stuff yet. All I've read is that RGB backlighting allows for color filterless "sequential" LCD driving. Seems like a good idea but I'm sure Tombaker, T2K....etc will be annoyed by the temporal color seperation since they are ultra-sensitive to flicker and temporal artifacts :)

If you have any info on RGB backlighting please post....

Cheers

I haven't gotten to the RGB stuff yet. All I've read is that RGB backlighting allows for color filterless "sequential" LCD driving. Seems like a good idea but I'm sure Tombaker, T2K....etc will be annoyed by the temporal color seperation since they are ultra-sensitive to flicker and temporal artifacts :)



If you have any info on RGB backlighting please post....

Cheers

Good one. Did you catch the poll where four people said that they did not notice any flickering, but that watching plasma made them feel 'weird'. Are you aware of any video panels viewer de-weirding technology break throughs in the pipeline.;)

I came across some stuff about the RGB LED LCD R&D back some time ago. I am not sure if I can find it now. If I do, I will post the details.

Thanks for all the great research.

I haven't gotten to the RGB stuff yet. All I've read is that RGB backlighting allows for color filterless "sequential" LCD driving. Seems like a good idea but I'm sure Tombaker, T2K....etc will be annoyed by the temporal color seperation since they are ultra-sensitive to flicker and temporal artifacts :)

If you have any info on RGB backlighting please post....

Cheers

Here is a link to one US Company that is doing R&D on RGB LED LCD HDTV Displays.

I will see if in can find any technical papers on the subject. You are probably best suited to scour the patents arena.

http://sysviewtech.com/led.asp



Introduction
Recently, LCD technology has become one of the dominant forces in large size flat panel display market due to the excellent performance in picture quality, ergonomics, reduced energy needs, space-saving and low cost of ownership benefits. LCD monitors or TVs can now be used for wide color space applications, which have historically been the domain of CRTs. The principle of operation of a traditional LCD display is based on placing a bright white-CCFL(Cold Cathode Fluorescent Lamp) light source behind a series of color matrix LC filters. The matrices are controlled digitally to provide fine adjustment of the light throughput, and therefore generate a grey scale image retrieving its color due to the color filters in front of the LCD. The backlight thus determines the color temperature and color space available, which has typically been approx 72% of the NTSC color space (CRT monitors achieve around 84% NTSC).

The innovative RGB LED backlight, consisting of red, green and blue LEDs (Light Emitting Diodes), generates white light allowing a wider range of spectral colors to be displayed. More than 100% of the NTSC and Adobe RGB color space can now be reproduced with an LCD monitor or TV using LED backlight! On top of this, the LED backlight allows end users to accurate adjust the white point by varying the ratio of the red, green and blue mixture, which is difficult to do with conventional CCFL backlighting. A feedback color management system ensures that the display operates consistently with a pre-defined color point over time and between units.
http://sysviewtech.com/led.asp

interesting (but I don't think Dolby has any customers for it yet)

Dolby Contrast or Dolby Vision (http://avsforum.com/avs-vb/showthread.php?p=12357534)

Here is a current article which reports Dolby has announced a new partnership to develop their product.

http://www.displaydaily.com/index.php

SIM2 Multimedia and Dolby Laboratories, Inc. have announced that the two companies are collaborating to develop new prototype high dynamic range (HDR)-enabled liquid crystal display (LCD) flat screens using Dolby’s new LED local dimming technology. In addition, SIM2 will provide Dolby with manufacturing reference designs.


The new prototype displays will feature Dolby’s dynamic range imaging technologies, Dolby Contrast and Dolby Vision. According to a Dolby press release, Dolby Contrast uses LEDs with local dimming to provide "dramatically enhanced" contrast. Dolby Vision combines high brightness with enhanced contrast to deliver "picture quality that virtually matches real-world visual perception of depth, detail, and color." The technology is said to preserve detail in dark areas, a known shortcoming of many display technologies. According to Dolby, its technologies were designed to leave implementation partners with a wide range of options to develop differentiated performance levels.
http://insightmedia.info/images/DD-2007-12-03.jpg
Apparently developing a role as a component supplier, SIM2 is set to offer manufacturing reference designs to other display manufacturers. The company said it plans to start by developing a 46-inch prototype panel, and is studying the possibility of bringing the technology into the market by the third quarter of 2008. Model or brand specifics have not been announced. The Dolby technology was first announced at last fall’s CEATEC Show in Japan; SIM2 is its first implementation partner, according to Bharath Rajagopalan, Dolby Image Technologies business line director. Dolby will be meeting with the press this month to discuss further details of this technology.
With Samsung recently announcing several new LED-backlit HDTV LCD panels, said to offer dynamic contrast ratios up to 500,000:1, it is not generally known how similar the Dolby and Samsung technologies may be. Sony, JVC and LG.Philips, among others, have also announced high-contrast LED/LCD technologies, the latter claiming "1,000,000:1 contrast" using local dimming technology.
While SIM2 introduced various LCD flat-panel displays 2.5 years ago, it is known primarily for its high-performance home theater front-projection systems. Similarly, Dolby has little history or experience in the LCD display world, but is a powerhouse for audio and film technologies. With this announcement, the two companies appear to have forged a strategic alliance that capitalizes on their strengths. Dolby has built a formidable business based on technology licensing-its licensing division is a model for how to extract long-lasting value from intellectual property. And SIM2 has a good track record with image quality.
While several companies appear to be working on similar technologies-presumably with unique approaches-the mainstream success of the products, regardless of performance, will depend on how cost effective they are. We’ve already seen LCD displays that are backlit by arrays of LEDs, with impressive results. However, straight economics that tells us that an array of thousands of high-output LEDs, together with appropriate light-coupling structures, is currently expensive to implement. Perhaps the Dolby approach (or others) addresses this issue by means of a clever solution. As they say, the proof of the pudding …

http://insightmedia.info/images/DD-2007-12-03.jpg
I'm assuming that is a picuture of the diffuser plate covering the LED array. If so that shows me that even with dolby vision the static contrast will vary widely across the screen due to the still apparent crosstalk. I'm sure pixel compensation will help but not completely solve the issue.

I'm assuming that is a picuture of the diffuser plate covering the LED array. If so that shows me that even with dolby vision the static contrast will vary widely across the screen due to the still apparent crosstalk. I'm sure pixel compensation will help but not completely solve the issue.

I do not know what that picture depicts. The article did not explain what it was demonstrating.

I am wondering if perhaps this whole LED, even the RGB approach, will not get implemented at a reasonable production cost level, before it gets overtaken by OLED developments. Do you have any thoughts on how well the OLED approach stacks up compared to using LED backlighting on LCD panels?

Does anyone have any actual viewing experience with this NEC LED RPG LCD Monitor?

http://www.nec-display-solutions.com/coremedia/generator/index,realm=Home__Details,spec=x__hq__en,docId=114920


http://www.nec-display-solutions.com/gfx/nav_butt_subnav_d.gif (http://www.nec-display-solutions.com/)Portal Site NEC Display Solutios Erope GmbH



http://www.nec-display-solutions.com/coremedia/images/dummy.gifhttp://www.nec-display-solutions.com/coremedia/generator/Internet/Shared/Images/HeadquarterShadowLeft,property=Value.jpgNEC Display Solutions presents high-end LCD NEC SpectraView Reference 21 with LED backlight technology
http://www.nec-display-solutions.com/coremedia/images/dummy.gifMunich, June 2005 – With the NEC SpectraView Reference 21 (SpectraView LCD2180 WideGamut LED), NEC Display Solutions Europe for the first time presents a ready-to-launch 21.3-inch LCD monitor with LED backlight technology. With this LCD display, which is equipped with a colour calibration system for accurate colour matching, NEC Display Solutions has taken a giant step in display technology. The basis for the SpectraView Reference 21 is the Super Advanced Super Fine Technology (SA-SFT) Dual-IPS panel and LED backlight technology. The technical challenge has been to develop display technology that covers more than 100% of the Adobe® RGB colour space and ensures absolute colour accuracy in all areas of colour processing on the monitor. Series production of the 21.3-inch LCD display with large colour space and integral LED backlight technology commenced at the beginning of June 2005, and it is therefore available in the shops with immediate effect.

Recent technology advances in digital image acquisition, colour-processing systems, colour printers, and other photographic I/O devices have been little short of remarkable. As well as ever-higher resolutions, the range and depth of colour reproduction has also shown significant improvements. A standardised colour space promises the benefit of consistent colour reproduction across all digital platforms and devices - the so-called colour workflow - from the point of acquisition to the point of delivery. Accurate colour consistency in an as large as possible colour space is required for professional users from the DTP and colour-proofing areas, as well as for the use of special devices for image processing and also industrial 4-colour printers. These requirements are now fulfilled by the introduction to the market of the NEC SpectraView Reference 21.

The start of the digital chain, i.e. image acquisition, has successfully adopted the Adobe® RGB colour space, and printing or hardcopy printing technology has been able to follow suit. The technical challenge for NEC Display Solutions has been to develop a monitor technology that complies with the Adobe® RGB colour space, and ensures absolute colour accuracy in all areas and stages of colour processing.

NEC SpectraView Reference 21 (SpectraView LCD2180 Wide Gamut LED)

In recent years, LCD technology has become the dominant force in the display market due to the excellent performance in picture quality and ergonomics, reduced energy needs, space-saving and low cost of ownership benefits. New developments mean that LCD monitors can now be used for wide colour space applications, which have historically been the domain of CRTs. The principle of operation of a traditional LCD screen is based on placing a bright white-light source (typically a mercury-filled fluorescent tube) behind a series of colour matrix LC filters. The LCD filter matrices are controlled digitally to provide fine adjustment of the light throughput, and therefore generate a greyscale image retrieving its colour due to the colour filters in front of the LCD. The backlight thus determines the colour temperature and colour space available, which has typically been approx 72% of the NTSC colour space (CRT monitors achieve around 84% NTSC).

The innovative RGB LED backlight, consisting of red, green and blue LEDs (Light Emitting Diodes), generates white light allowing a wider range of spectral colours to be displayed. More than 100% of the Adobe RGB and NTSC colour space can now be reproduced with an LCD monitor! On top of this, the LED backlight allows for accurate adjustment of the white point between 5000K and 9300K without loss of brightness, as the LCD layer does not change the white colour temperature as in the case of LCDs with conventional CCFL backlighting, but the LED backlight itself is capable of changing its white point by varying the ratio of the red, green and blue mixture. A feedback sensor ensures that the display operates consistently with a pre-defined performance. As a result of this feedback system, the monitor does not need a warm-up phase, but displays stable colours after just a minute. The new mercury-free LED backlight system and the optimized colour filters of the LCD generate an enhanced colour space allowing a wider range of spectral colours to be displayed – the Adobe® RGB colour space can be more than covered and therefore consistently reproduced. This innovative solution has been developed by NEC-Mitsubishi in close cooperation with professionals from the colour processing industry. The SpectraView Reference 21 is now the world's first LCD monitor with LED backlight for the colour management market.

With the new NEC SpectraView Reference 21, NEC Display Solutions therefore provides the optimum solution for demanding users in the colour management sector with a very wide colour space, a screen diagonal of 21.3 inches, and a high resolution of 1600 x 1200 pixels. In addition, a high-accuracy internal feedback system for colour calibration has been integrated to control colour temperature and brightness. The backlight system thus achieves a delta-E of below 1 within less than one minute. The new NEC SpectraView Reference 21 is equipped with a Dual-Domain S-IPS panel, the Super Advanced Super Fine Technology (SA-SFT) panel produced by NEC LCD Technologies, which provides high-speed response times and ultra-wide viewing angles with less colour shift.

The integrated 10-bit gamma table allows an accurate gamma correction function – one each for red, green and blue – for optimum hardware calibration. 1,021 tonal values per colour mean that gradation adjustment is much more precise. Even the most subtle tonal value gradations and greyscales are displayed with extraordinary precision and clarity, which enables the highest quality of colour accuracy to be achieved. Also integrated into the NEC SpectraView Reference 21 is the ColourComp function, a colour uniformity correction improving the Delta-E (colour uniformity variances), which is already improved in the factory by profile validation. These measurement results are interpolated to correct the colour uniformity of each of the 1600x1200 pixels. This correction function is uploaded to the hardware of each monitor.

As users working with demanding applications e.g. in the pre-press segment, remote proofing or textile design, need absolutely accurate colours, it was the target of NEC Display Solutions to provide a monitor for these users with the latest technology available, and thus provide innovative solutions in this area.

Hardware calibration without compromises

With exceptional features, the SpectraView Profiler software supplied with the unit allows the brightness and the white point to be calibrated, and thus creates the ICC profiles.

· L* calibration (CIELAB L* colour model)
· Iterative calibration
· LUT-based 16-bit ICC profile instead of matrix profiles
· Supports most known sensors
· Profile validation
· White point adjustment
· Greyscale calibration
· Optional gamut compression

Included with each monitor is the light shield, secured by magnetic strips, the SpectraView Profiler software, digital cable and the SpectraView Certifier certification document with the proven and tested performance characteristics recorded for each individual unit during final inspection.

NEC Display Solutions Europe GmbH

NEC Display Solutions Europe GmbH with its headquarters in Munich, Germany, is a 100 percent subsidiary of the NEC Corporation, Tokyo. The company, established on 1st April 2005, is a product of the joint venture between NEC Corp. and Mitsubishi Electric – NEC-Mitsubishi Electronics Display-Europe GmbH – in the monitor sector. In Europe, NEC Display Solutions Europe GmbH has subsidiaries in Germany for Central, East and South-east Europe, in France and Great Britain as well as sales offices in Italy, the Netherlands, Russia, Spain, Sweden and Poland. The business benefits from the technological know-how and the technologies of the NEC Corporation and, with its own Research and Development, is one of the world's leading manufacturers of desktop-monitors, also for colour-critical applications, large-format LCDs – so-called Public Displays – and special displays for the medical field. CEO of NEC Display Solutions, Ltd, Japan, is Hirotoshi Matsuda. The company employs more than 1,500 staff world-wide. Managing Director of the European headquarters is Noboru Akagi. You will find more information under www.nec-display-solutions.com (http://www.nec-display-solutions.com/)

NEC Corporation (NASDAQ: NIPNY, FTSE: 6701q.1, TSE: 6701) is a leading supplier of information and telecommunications technology. The enterprise numbers amongst the Global Fortune 500 companies with the most patent applications world-wide. NEC develops tailor-made solutions for its customers for the networked world: the range of performances includes the development of semiconductor base technology, setting up and servicing of large-scale systems, system integration as well as the provision of mobile and broadband technology. NEC employs more than 140,000 staff. More information is available under: http://www.nec.com (http://www.nec.com/).

Specifications for the SpectraView Reference 21 (SpectraView LCD2180 WideGamut LED) – 21.3-inch LCD monitor with LED backlight:

Feature
Specification
LCD
21.3-inch LCD Dual Domain IPS
Light source
Lumileds Lighting Luxeon DCC – RGB LED Array
Dot pitch
0.27 mm
Resolution
1600 x 1200
Colour gamut
More than 100% Adobe® RGB (up to 105.7% Adobe® RGB; up to 101.0% NTSC)
Brightness
200 cd/m2 (typ.) @ 5000K - 9300K*
Contrast ratio
430:1 (standard)
Response time
20 ms (typ.) (Ton + Toff)
Viewing angle
176° hor. / 176° vert. (typ., at > 10:1 contrast)
Input video signal
2 x Digital DVI
Shipping content
Removable hood, SpectraView Profiler software, digital cable, SpectraView Certifier certification
* Colour uniformity correction in "Off" mode

For further press information:

Sabine Meinitz, Corporate Communications Manager Europe
NEC Display Solutions Europe GmbH
Landshuter Allee 12-14
80637 Munich
Tel: +49+89/99 699-0
Fax: +49+89/99 699-500
E-mail: sabine.meinitz@nec-displays.com


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I'm assuming that is a picuture of the diffuser plate covering the LED array. If so that shows me that even with dolby vision the static contrast will vary widely across the screen due to the still apparent crosstalk. I'm sure pixel compensation will help but not completely solve the issue.Keep in mind that, according to what BrightSide folks have found, there exists a maximum number of zones beyond which there can be no discernible difference in PQ so, say, a set with backlight having 1400 individually modulated zones would look as good as a set with backlight having equal number of zones and pixels. In other words, crosstalk becomes a non-issue once you have individual LED modulation. Samsung's 81 series has backlights with only 64-192 zones so the crosstalk is a problem there. Besides, Samsung's LEDs have, according to one paper, only 64 brightness levels while, BrightSide has always used LEDs with 256 brightness levels.

LUV...
all this tech stuff!!! :cool:

GREAT thread.
Looking forward to good news from CES. :D

Just...
now I'll have to wait till '09 to get a set! :p

I had HD in '00.
Canceled my replacement, cause it didn't have DVI,
then waited for 720p
then HDMI
then 1080p
then HDMI 1.3
then 120Hz
then LED backlight
then 5:5
then LED mufti zone backlight
then color LED backlight
now "Dolby" has the answer???

Gee, this hobby is FUN!?!?!?!? :)

crosstalk becomes a non-issue once you have individual LED modulation.We may not be on the same page when discussing crosstalk. From what I've read crosstalk is an issue with the LED diffuser combination. Light will be spead laterally whether it is one LED or a bunch of LEDs. The only way to fundamentally eliminate crosstalk is to remove the diffuser plate. Since that is not an option then compensation is the next best option.

xrox: for all the non tech people out here--if you had to take guess--how much do you believe LED dimming will improve and thereby improve Picture quality in next year's LCDs?

I still favor plasma but LCD is starting to suck less and less--who knows--maybe one day it will be great?

xrox: for all the non tech people out here--if you had to take guess--how much do you believe LED dimming will improve and thereby improve Picture quality in next year's LCDs?

I still favor plasma but LCD is starting to suck less and less--who knows--maybe one day it will be great?Just guessing but I would say if compensation is used, a significant improvement "may" result regarding LED dimming problems. That is why I started the thread, that is to find out when or if compensation is being used.

I still prefer the idea of an emissive display versus a passive display like LCD as I've never really liked the concept of backlighting. But the hype regarding newer LED-LCDs has gotten me interested.

Just guessing but I would say if compensation is used, a significant improvement "may" result regarding LED dimming problems. That is why I started the thread, that is to find out when or if compensation is being used.

I still prefer the idea of an emissive display versus a passive display like LCD as I've never really liked the concept of backlighting. But the hype regarding newer LED-LCDs has gotten me interested.

Do you have any thoughts on if OLED may supplant the entire backlighing LCD approach. It looks like RGB LED displays are going to be very expense for the foreseeable future, which just might allow OLED technology to mature and become more affordable. What do you think?

Do you have any thoughts on if OLED may supplant the entire backlighing LCD approach. It looks like RGB LED displays are going to be very expense for the foreseeable future, which just might allow OLED technology to mature and become more affordable. What do you think?I guess it all depends on how long OLED will take. I've always feared that by the time OLED came to market in home theatre sized displays that the improvements in LCD and Plasma displays would narrow the performance leaps that OLED claims. I'm still uncertain on this but as of now OLED still does offer much more potential. Even the benefits of "ultra-thin" and "flexible" may be challenged by both LCD and Plasma futures. We'll have to see how LED-LCD and high lumen plasma evolve in the next few years as OLED start to come out. I'm personally rooting for OLED.

I guess it all depends on how long OLED will take. I've always feared that by the time OLED came to market in home theatre sized displays that the improvements in LCD and Plasma displays would narrow the performance leaps that OLED claims. I'm still uncertain on this but as of now OLED still does offer much more potential. Even the benefits of "ultra-thin" and "flexible" may be challenged by both LCD and Plasma futures. We'll have to see how LED-LCD and high lumen plasma evolve in the next few years as OLED start to come out. I'm personally rooting for OLED.

I am also rooting for it. At least Sony has now proved that it can be manufactured. Next they have to start to scale it up to larger panel sizes. There are so many different companies developing OLED panels that both size increase, and cost reduction may be accelerated due to such competitive pressures.

What display issues, that you are aware of, does OLED solve, and not solve?

What display issues, that you are aware of, does OLED solve, and not solve?Isochroma can give a better summary but off the top of my head:

Benefits

- brightness* (versus PDP)
- power consumption*
- black level (without artifacting**)
- viewing angle (versus backlighted displays)
- color reproduction
- response time
- weight and thickness
- Potential for ease of manufacture (ink jet printing)
- Potential for flexibility
- addressing speed***

* - LED-LCD and high lumen PDP may reduce this benefit
** - OLED is emissive meaning no crosstalk or black crush problems like LED-LCD
***- this benefit will ony be realized with longer life materials which allow for higher frame rates and less hold type blurring without adding flicker.

Drawbacks

- Differential EL material aging (blue much quicker than red or green means big color issues)
- Hold type display blurring (no benefit over LCD in this aspect)
- Mura (this is a new one to me but apparently OLED has a mura problem but can be solved by compensation)

That is why I started the thread, that is to find out when or if compensation is being used.

If we don't find out soon, hope this thread remains a HOT topic into January. So, we have the chance to hear something from CES.

xron,
What's your fave flat panel now ('07) & what would your guess be for next yr ('08)?
Thx.

What's your fave flat panel now ('07) & what would your guess be for next yr ('08)While far from perfect, the Elite Kuro 150FD to me is the best Flat Panel I could buy right now. Problem is there is none left to buy at the moment :(

Next year is not far away, but I still don't quite know what to expect? This year was definitely a good year for display technology though IMO.

Current article that provides a broad perspective on where things stand, and are headed in the LCD back lighting field. A little off topic, but it does shed some light (sorry for the bad pun) on the subject.

http://www.digitimes.com/displays/a20071206PR203.html

New technologies for television backlighting point to better performance, says iSuppli
Press release, December 6; Greg Wu, DIGITIMES [Thursday 6 December 2007] http://www.digitimes.com/Images/spacepx.gif
LCD TV makers are striving to differentiate their products and move the market to ever larger screen sizes, while rear-projection TV makers are trying to remain competitive against flat-panel TVs. Both groups increasingly are looking to advanced backlighting sources to deal with these challenges, according to discussions held at iSuppli's Flat Information Displays (FID) 2007 conference.
While LCD panels are able to scale down their costs as they get larger, lighting expenses have not declined as have the LCD panels. In fact, lighting costs have increased as a share of total cost in larger televisions.
This is of particular concern to the panel makers, which are absorbing most of the lighting costs. Panel makers also are moving toward using third-party lighting manufacturers to supply them, adding even more cost, according to iSuppli.
Current LCD TVs mostly utilize fluorescent light sources that consist of tubes and a series of optical films. On the plus side, these technologies have benefits in terms of life span, high efficiency and high production volume. On the negative side, there are no learning-curve economics for such sources and they contain mercury, which often violates the RoHS requirements. They also have slow start-up times, deliver a poor color gamut and rise in cost as displays get larger.
"LCD TVs need to improve picture quality in order to convince those consumers still tied to their CRTs or plasma displays," Semenza said. "Lighting is a key aspect to how the LCD TV market can remove remaining barriers to adoption."
From the cost perspective, as LEDs continue to fall in price, they can begin to provide savings, beginning with the largest screen sizes.
Getting the LED out
While many technologies are available for display lighting, including variations on fluorescent tubes, and emerging technologies such as field emission displays (FEDs) and organic light emitting diodes (OLEDs), it is the light emitting diodes (LEDs) that stand the best chance of improving LCD TV backlighting in the short term, according to iSuppli.
LEDs can be used as a direct replacement for standard fluorescent lamps, meaning they are the easiest to implement in terms of design changes and market entry.
Plus, employing time-sequential color in LEDs eliminates the need for color filters. Their capability to accurately control brightness of LEDs enables high dynamic range, a feature just being adopted at the high-end of the LCD TV market.
One problem, however, is that LEDs now are too expensive to be used in the mass market. iSuppli believes there will be significant cost reductions over the next few years, which will position LEDs as a mass market light source.
The high cost of LEDs will limit their use in LCD TVs during the near-term. Global shipments of LCD TVs with LED backlights will rise to 64,000 units by the fourth quarter of 2008, up from 42,000 in the fourth quarter of 2007.

Here is what "crosstalk" looks like in my mind :) Please excuse the poor drawing but I spent only 5 minutes.

http://i222.photobucket.com/albums/dd126/xrox/Crosstalk.jpg

As you can see even with a single LED activated the light spreads out laterally. This makes the static contrast drop whenever the LEDs turn on. Good luck showing stars in a night sky properly.

Compensation does help though.

Cheers

This year was definitely a good year for display technology though IMO.
Yeah, things are going in a great direction price point & quality wise.
Exciting times!
Enjoy.

Although I'm not a great fan of Dolby (even though its here in the Bay Area), I am looking forward to their (probably someone else's, although I don't know that for certain) implementation.

Who's knows?
We may be back to CRT quality by '09! :p

Here is what "crosstalk" looks like in my mind :) Please excuse the poor drawing but I spent only 5 minutes.

http://i222.photobucket.com/albums/dd126/xrox/Crosstalk.jpg

As you can see even with a single LED activated the light spreads out laterally. This makes the static contrast drop whenever the LEDs turn on. Good luck showing stars in a night sky properly.

Compensation does help though.

Cheers

Yes, but the light spill from the LED does not extend across the whole panel. It has a distinct point-spread-function type of profile, and diminishes rapidly as you move away from that LED.

What the Dolby technology is doing, which was developed by Brightside (you can see their white papers), is using algorithms to control both the backlight and the LCD panel in unison to create very high contrast images both in terms of on/off sequential contrast, and local instantaneous contrast (astronomically high ANSI CR numbers). It is not my understanding that the current Samsung LED backlit LCDs do this. I believe they simply modulate to some degree (but not nearly as much it seems) the LED backlighting. They may also have some local gamma changes to compensate a bit for that, but I don't think it's what Brightside is doing, because I am fairly certain they hold patents for that, which is why I assume Dolby bought them.

So as it stands now, if you look at the samsung LEDs, you can see the effects of the LEDs dimming and brightening, because it is not fully compensated for. The Brightside technology pushes any local spill from the LED down below the visible threshold. In this way, they can create (and it is very impressive to see) an extremely bright white square or object on a completely black background. What is amazing about this, is that when you look at this kind of pattern, you do see spill extending around the sharp edges of the square, but the spill is actually light spill in your eyes, not actually in the display. If you obstruct the white pattern element from your vision, you can observe a small amount of spill just around the edges of the square, however it is not visible because the spill of your eyes exceed it. It is in this way that they can display truly HDR images in a manner that exceeds our visual capabilities to discern the technical weaknesses in the display. Part of the way they're able to do that is by using enough LEDs, if there are too few, than you don't have local enough control, and the spill in the display will begin to approach or exceed the spill in our eyes, thus it will become visible.

I am very excited to see what Sim2 will unveil. Having seen the Brightside HDR, it should be extremely impressive, and quite radically different than anything anyone has seen before. The current Samsung LEDs don't even remotely come close to what the Brightside HDR does. But they don't cost $50K either and have a crazy cooling system. ;)

What is amazing about this, is that when you look at this kind of pattern, you do see spill extending around the sharp edges of the square, but the spill is actually light spill in your eyes, not actually in the display. If you obstruct the white pattern element from your vision, you can observe a small amount of spill just around the edges of the square, however it is not visible because the spill of your eyes exceed it.

This is called "veiling glare", caused by "flare" of the strong light inside of your eyeball.

This is called "veiling glare", caused by "flare" of the strong light inside of your eyeball.

Yup.

If you obstruct the white pattern element from your vision, you can observe a small amount of spill just around the edges of the square, however it is not visible because the spill of your eyes exceed it.

Wouldn't the overspill just exaggerate the eye's natual halo (is light cumulative?).

An argument i've heard (regarding the 81 series) is that the halos are "natural" and therefore OK.

I hesitate to accept this because he same argument is used to justify blurry LCDs and digitized motion blur -
"it's natural. The display should blur just like the eye does"

I disagree in the case of motion blur - The eye will blur things naturally and tracked objects shouldn't blur - ever. IMO bad logic there.

Hmm then again I guess unnatural brightness is the whole point of HDR isn't it...unless wer'e talking about a TRUE HDR display.

Yes, but the light spill from the LED does not extend across the whole panel. It has a distinct point-spread-function type of profile, and diminishes rapidly as you move away from that LED. Sorry if I suggested that one LED uniformly lights up the entire diffuser. There is definitely a point spread function that is wide compared to the pixel dimensions though. I Have a plot of the point spread if you need to see it.

Edit: Actually my drawing clearly shows the point spread phenomenon :)

What the Dolby technology is doing, which was developed by Brightside (you can see their white papers), is using algorithms to control both the backlight and the LCD panel in unisonThis is explained several times in this thread. The difference between samsung and Dolby is that Dolby uses LED and pixel compensation (depending on which dolby version). Look back in the thread it is already explained.


So as it stands now, if you look at the samsung LEDs, you can see the effects of the LEDs dimming and brightening, because it is not fully compensated for. The Brightside technology pushes any local spill from the LED down below the visible threshold.LED compensation may do this if done perfectly but the result is non-uniform luminence. The LEDs have to be dimmed to reduce the visibly spread pattern o the diffuser. Combine with some fancy pixel compensation and the result may be more uniform. And as you increase the viewing angle the light spread on the diffuser becomes much more visbible.


In this way, they can create (and it is very impressive to see) an extremely bright white square or object on a completely black background. What is amazing about this, is that when you look at this kind of pattern, you do see spill extending around the sharp edges of the square, but the spill is actually light spill in your eyes, not actually in the display. If you obstruct the white pattern element from your vision, you can observe a small amount of spill just around the edges of the square, however it is not visible because the spill of your eyes exceed it. It is in this way that they can display truly HDR images in a manner that exceeds our visual capabilities to discern the technical weaknesses in the display. Part of the way they're able to do that is by using enough LEDs, if there are too few, than you don't have local enough control, and the spill in the display will begin to approach or exceed the spill in our eyes, thus it will become visible. As i've said many time LED and pixel compensation have promise.

The current Samsung LEDs don't even remotely come close to what the Brightside HDR does. But they don't cost $50K either and have a crazy cooling system. ;)Yes but Samsung has developed a pixel compensation (see first post) method that may or may not be implemented in next gen models. If so the only difference between samsung and Dolby will be LED compensation.

What the Dolby technology is doing, which was developed by Brightside (you can see their white papers), is using algorithms to control both the backlight and the LCD panel in unison to create very high contrast images both in terms of on/off sequential contrast, and local instantaneous contrast (astronomically high ANSI CR numbers) I have static contrast numbers for Pixel compensated LED dimming and they are still extremely variable due to the diffuser optics. They range from 20,000:1 to 500:1 depending on distance from active LEDs. LED compensation will help alot but not solve this issue especially with increasing viewing angles.

Wouldn't the overspill just exaggerate the eye's natual halo (is light cumulative?).

An argument i've heard (regarding the 81 series) is that the halos are "natural" and therefore OK.

I've seen BrightSide's demonstration of their technology. I did not see the LED spill accumulating with the flare in the eye. The flare in the eye masks the LED spill completely.

They do a simple example: A full white square is shown on the monitor, surrounded by full black. When you first see this, you see a lot of glare around the white square and you think, "Wow, those LED's are really overshooting and turning what is supposed to be black into gray!" Then, you take a thick black card and hold it to the edge of the white square, and the glare looks identical. That makes it obvious just how much flare occurs in the eye. You can also take the black card and cover the white square, and see how much overspill is happening from the LED's. It is a lot. But when you redo the glare test, you realize that the overspill just does not matter. The glare in your eye veils it.

The amount of flare in the eye is measurable. It depends on the difference in contrast at the edge, viewing distance, and size of the bright area. To implement local dimming properly, you must make the LED zones an appropriate size, based on the viewing distance.

The Samsung 81 series is a poor implementation. They have something like 64 zones on 52 and 57 inch displays. BrightSide's 37 inch monitor has over 300 zones. The Samsung's zones are too big, which makes the halos big enough that they overshoot the veiling glare. Also, Samsung does not appear to modulate both the LED's and LCD properly. This results in weird color shifts and uneven brightness.

Wouldn't the overspill just exaggerate the eye's natual halo (is light cumulative?).

No, the spill in your eyes is significantly greater, it is not possible to see the actual spill that is occurring in the display. It's like trying to see details in the dark with a bright light shining in your eyes, there may be details (artifacts) there, but you are not capable of seeing them. That's the trick to pull off the HDR display is that it truly exceeds your visual capabilities.

An argument i've heard (regarding the 81 series) is that the halos are "natural" and therefore OK.

I disagree, IMO, at least on the Samsungs. I prefer to turn the dynamic LED dimming off. But I've been talking mainly about the implementation in the brightside HDR, and what I hope to see from Sim2 using that technology, which is quite distinct.


I hesitate to accept this because he same argument is used to justify blurry LCDs and digitized motion blur -
"it's natural. The display should blur just like the eye does"

I agree, but it's not like that at all in terms of what I'm talking about (not the samsungs).

I disagree in the case of motion blur - The eye will blur things naturally and tracked objects shouldn't blur - ever. IMO bad logic there.

And you're correct.

Hmm then again I guess unnatural brightness is the whole point of HDR isn't it...unless wer'e talking about a TRUE HDR display.

That is what I'm talking about. ;)

It's like trying to see details in the dark with a bright light shining in your eyes, there may be details (artifacts) there, but you are not capable of seeing them.

So the only halos seen are those that come naturally from the eye. The screen halos don't play a part in the HDR simulation and in fact are not to be seen - that makes sense. You know I was remembering certain games (maybe now video too) that actually add halos in the content to simulate HDR effects - I see that's completely different than what an HDR display does. thx!

Now that there are 3 or 4 new LED local dimming panels being released I'd like to start discussing/updating this thread. We can discuss how/if new LED or pixel compensation techniques are being used and if they actually make any improvement. Please post any info that you have (with reference if possible)

Cheers

I hear that LED dimming is currently divided into "zones".

Is there any development underway for "per-pixel" dimming ?

I hear that LED dimming is currently divided into "zones".

Is there any development underway for "per-pixel" dimming ?

Dolby Vision. However, I can't say whether this technology will ever come to the mass market anytime soon.

Dolby Vision. However, I can't say whether this technology will ever come to the mass market anytime soon.And thats without saying what price it will be at :eek:

I hear that LED dimming is currently divided into "zones".

Is there any development underway for "per-pixel" dimming ?Per-pixel dimming is way beyond overkill. The display currently with the most zones (1836) is Sim2 LCD with Dolby Vision/Contrast local dimming technology.

What's the real difference between LED (as used in LED backlights for LCDs) and OLED, apart from that the later is organic? Couldn't they just make a TV with many LEDs instead of using them for back-lighting an LCD HDTV? Or are there problems with that (like can't they be made small enough or does it need lots more circuitry or would it be much too costly etc. and how is that solved with OLED?)

Per-pixel dimming is way beyond overkill. The display currently with the most zones (1836) is Sim2 LCD with Dolby Vision/Contrast local dimming technology.

I've just visited LCD topics section, here aned read that the new samsung 950 has ahem 64 ? zones, apparently LESS THAN WHAT THEY HAD LAST YEAR. So how do you like it compared to 1836 zones when it's done properly?

I've just visited LCD topics section, here aned read that the new samsung 950 has ahem 64 ? zones, apparently LESS THAN WHAT THEY HAD LAST YEAR. So how do you like it compared to 1836 zones when it's done properly?

Judging from this year sets we are in post-zone era:cool:. Meaning that algorithms for controlling LED clusters got so sophisticated that this year sets have virtually no dimming artefacts or they are reduced to become no-issue except for perverts who hunt them with magnifying glass:D . It is not clear how big improvement in dimming was achieved. There is talk about 'ovelapping' zones, 'soft' zones etc.

Judging from this year sets we are in post-zone era:cool:. Meaning that algorithms for controlling LED clusters got so sophisticated that this year sets have virtually no dimming artefacts or they are reduced to become no-issue except for perverts who hunt them with magnifying glass:D . It is not clear how big improvement in dimming was achieved. There is talk about 'ovelapping' zones, 'soft' zones etc.
I don't think you need a magnifying glass to be able to count 64 zones. The people who own the sets with 64 zones easily counted the number of zones using a white cursor against a black background.

To properly display a star field etc. I think you'd need a couple more than 64 zones. If you look on amazon uk people are complaining about the problems displaying the cursor in the Matrix movies on a Samsung set that has 96 zones. I'd guess it would be more of a problem on a set with only 64 zones.

The more I research LED dimming LCDs the more interesting they become. I still don't think it will ever be perfect with a light diffuser plate, no matter how sophisticated the pixel and LED compensation becomes. But nothing will be perfect I guess. Another problem I have is that it is rather complex (convoluted if you will) to have two seperate matrix driven panels (LED and LCD). I suspect if LD-LCD does become dominant that there will be a strong drive to supercede it as it is way too complex a display system.

Currently I still cannot get myself to like backlit sets (the whole fluorescent sign look to them) but my hopes are getting stronger for LD-LCD.

There can be no substitute for large zone count even if each zone had thousands of brightness levels just like 480p can't be a substitute for 1080p.

Current LCDs with local dimming will probably look quite primitive next to sets with 2000 color zones (each zone consisting of individually adjustable RGB LEDs) with at least 8-bit depth per zone. XBR8, the most advanced LCD with LD on the market today, has only 170 black and white zones.

I still don't think it will ever be perfect with a light diffuser plate, no matter how sophisticated the pixel and LED compensation becomes.

I agree. LCDs have some fundamental issues that are exacerbated by playing with spatial modulation of contrast in the backlight, and there's nothing much that can be done about it short of strictly limiting backlight contrast. Which tends to defeat the purpose.

They probably can, however, become "good enough" for consumer applications. Whether this will happen at a suitable price before OLED or some other tech finishes off high end LCD is a question only time can answer. My guess is that local dimming will end up being a stop-gap with a relatively short lifespan, but there is no way to really know for sure.

Samsung has already displayed a panel that does 8k:1 without needing any backlight games. Whether that's a one-off or something that can be produced cheaply in quantity is an open question. D-Nice has excited many with his crystal-balling of upcoming plasma improvements.

The other question is just how much contrast do you need? Film tops out around 4k:1, which is within spitting distance of the latest crop of LCDs which are hitting around 2k:1 native (at least from straight on). The studies I've read suggest somewhere around 10k:1 the eye starts running out of contrast perception on short timeframes on par with "typical" film scene length (the number is much higher over very long timeframes, of course, and even the 10k number is not exactly a consensus).

And we all know about contrast destruction in less-than-black viewing environments. One way to preserve contrast in less than ideal conditions is to simply pump out more light - this is why the old Brightside prototype could look so good on a tradeshow floor - with 4000 nits it could simply overpower the ambient conditions for a near 10x improvement in perceived contrast relative to the typical 400 nit display.

But what do you do with 4000 nits in a home theatre setting?! You'll burn your eyeballs out.

IMO the company that knows more about local dimming tech than any other is Sharp; I look forward to seeing third-party reviews of their recent product release.

I agree. LCDs have some fundamental issues that are exacerbated by playing with spatial modulation of contrast in the backlight, and there's nothing much that can be done about it short of strictly limiting backlight contrast. Which tends to defeat the purpose.

They probably can, however, become "good enough" for consumer applications. Whether this will happen at a suitable price before OLED or some other tech finishes off high end LCD is a question only time can answer. My guess is that local dimming will end up being a stop-gap with a relatively short lifespan, but there is no way to really know for sure.

Samsung has already displayed a panel that does 8k:1 without needing any backlight games. Whether that's a one-off or something that can be produced cheaply in quantity is an open question. D-Nice has excited many with his crystal-balling of upcoming plasma improvements.

The other question is just how much contrast do you need? Film tops out around 4k:1, which is within spitting distance of the latest crop of LCDs which are hitting around 2k:1 native (at least from straight on). The studies I've read suggest somewhere around 10k:1 the eye starts running out of contrast perception on short timeframes on par with "typical" film scene length (the number is much higher over very long timeframes, of course, and even the 10k number is not exactly a consensus).

And we all know about contrast destruction in less-than-black viewing environments. One way to preserve contrast in less than ideal conditions is to simply pump out more light - this is why the old Brightside prototype could look so good on a tradeshow floor - with 4000 nits it could simply overpower the ambient conditions for a near 10x improvement in perceived contrast relative to the typical 400 nit display.

But what do you do with 4000 nits in a home theatre setting?! You'll burn your eyeballs out.

IMO the company that knows more about local dimming tech than any other is Sharp; I look forward to seeing third-party reviews of their recent product release.The Sharp product does look very interesting. I think that Samsungs 81 series was a bit of a flop as they expected it to be a breakthrough product when in fact consumers perferred the 71 (non LD) for various reasons.

If you look at the first post of this thread the technology described was developed by Samsung yet it is still not in a product as far as I can tell?? Maybe just too expensive.