What causes the banding on 55LE8500? - AVS Forum
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post #1 of 21 Old 12-30-2010, 07:01 PM - Thread Starter
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Hi, I recently purchased an LG 55LE8500 and I'm very dissatisfied with the banding issue... on light, solid colored backgrounds, it's horrible. It also does it on movies when the camera moves a certain way.

Does anyone know the cause on this unit? I've heard the local dimming might be one cause... I'm looking for a nice LED around 55" that absolutely does NOT have a banding issue on light, solid colored backgrounds - because I will use this a lot with my computer and the internet in particular which has tons of white or light colored space on the sides of webpages.

Any info on this matter would be greatly appreciated, thanks!
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post #2 of 21 Old 12-30-2010, 09:33 PM
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It has to due with the way LG designed the optics and diffusers and how it operates with the dimming zones.
For one, the IOP construction was a problem. LG has a glass plate over the LCD, just like the Sony monolithic design, however there's an air gap between the glass and the LCD on the LG. The Sony, on the other hand, filled the air gap with a clear resin (known as OptiContrast) to eliminate any ghosting images, provide clearer image/color, and a better overall ARfilter.
Just like I mentioned above, a perfect set of optics and diffusers are necessary for the light to be focused properly, and it's necessary for it to blend the lighting throughout the screen. Perhaps the dimming zones were far to close to the display, and so the horizontal zone banding is very apparent.

The Sony HX909, the other only LCD set with full back-lit local dimming does not suffer any zone banding. I guess Sony knows how to properly align and design the sets to prevent any apparent zone banding... and the OptiContrast display works wonders.
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post #3 of 21 Old 12-30-2010, 09:49 PM
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Quote:
Originally Posted by NoBandingPlz View Post

Hi, I recently purchased an LG 55LE8500 and I'm very dissatisfied with the banding issue... on light, solid colored backgrounds, it's horrible. It also does it on movies when the camera moves a certain way.

Does anyone know the cause on this unit? I've heard the local dimming might be one cause... I'm looking for a nice LED around 55" that absolutely does NOT have a banding issue on light, solid colored backgrounds - because I will use this a lot with my computer and the internet in particular which has tons of white or light colored space on the sides of webpages.

Any info on this matter would be greatly appreciated, thanks!

Seems like you are seeing it on static images - which is very surprising. I definitely see it when the camera pans on scenes with gradually contoured backgrounds - but never on solid backgrounds or static scenes.

What causes it - not sure - but the fact it appears on panning scenes would indicate that something on the local diming algorithms finds it hard when passing the image from zone to zone. Not sure I buy the optical explanation as this would show the effect on static images,
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post #4 of 21 Old 12-30-2010, 10:20 PM - Thread Starter
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Originally Posted by undecided View Post
Seems like you are seeing it on static images - which is very surprising. I definitely see it when the camera pans on scenes with gradually contoured backgrounds - but never on solid backgrounds or static scenes.

What causes it - not sure - but the fact it appears on panning scenes would indicate that something on the local diming algorithms finds it hard when passing the image from zone to zone. Not sure I buy the optical explanation as this would show the effect on static images,
So you have an LE8500... and you don't see the horizontal banding on light, solid colors?

I have a laptop hooked up with HDMI and when I open a web browser... there are lots of spots where the screen is all white or another very light color and the horizontal banding is horrible... it seems like when you blink or move your head it has a sort of strobe effect. You don't get that on your tv? Or have you never looked at large, light colored areas on the screen?

I might be able to live with the banding on movies - but the kind of banding on the light, solid colored areas is just too much to take.
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post #5 of 21 Old 12-30-2010, 10:23 PM
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Quote:
Originally Posted by undecided View Post
Seems like you are seeing it on static images - which is very surprising. I definitely see it when the camera pans on scenes with gradually contoured backgrounds - but never on solid backgrounds or static scenes.

What causes it - not sure - but the fact it appears on panning scenes would indicate that something on the local diming algorithms finds it hard when passing the image from zone to zone. Not sure I buy the optical explanation as this would show the effect on static images,
It hardly has anything to do with the software associated with the control of local dimming algorithms, as it more of a hardware problem. If not, then LG would have already had the capability of fixing this "issue" via firmware update.
If the system did have troubles pre-calculating the zones to accommodate the image in a steady rate, then their software is lacking any technicality and speed/efficiency... But even so, that wouldn't explain why vertical banding is apparent.

Local dimming, especially the thin displays, require light guides (hence, zones) to diffuse the light thoroughly. Or else you'll see extremely bright little dots in unison around the screen! And these light guides (sections) are the cause of these zone banding because edges of these light plates accumulate an excess of light.

The vertical banding will theoretically still be present even on static images, given the fact that these images are generally lacking gradients (such as solid colors or full screen sources) However, even images with no gradient would, I assume, still show this effect to some degree. The fast pace movement would show this affect more profoundly given the circumstances.

It's an internal hardware issue and the way they designed the television.
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post #6 of 21 Old 12-30-2010, 10:26 PM - Thread Starter
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But also as a side note... it seems like every TV out there has some flaw, whether it's banding or blooming or uniformity issues... bleeding... ghosting etc.

Are there really no high-end flat panel tvs without such obvious flaws? I just don't get it.
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post #7 of 21 Old 12-31-2010, 12:03 AM
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Quote:
Originally Posted by Do-It-Yourself View Post
It hardly has anything to do with the software associated with the control of local dimming algorithms, as it more of a hardware problem. If not, then LG would have already had the capability of fixing this "issue" via firmware update.
If the system did have troubles pre-calculating the zones to accommodate the image in a steady rate, then their software is lacking any technicality and speed/efficiency... But even so, that wouldn't explain why vertical banding is apparent.

Local dimming, especially the thin displays, require light guides (hence, zones) to diffuse the light thoroughly. Or else you'll see extremely bright little dots in unison around the screen! And these light guides (sections) are the cause of these zone banding because edges of these light plates accumulate an excess of light.

The vertical banding will theoretically still be present even on static images, given the fact that these images are generally lacking gradients (such as solid colors or full screen sources) However, even images with no gradient would, I assume, still show this effect to some degree. The fast pace movement would show this affect more profoundly given the circumstances.

It's an internal hardware issue and the way they designed the television.
Algorithms can be implemented in hardware or software - I still maintain I have never seen it on a solid color or static image - have you?
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post #8 of 21 Old 12-31-2010, 12:08 AM
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Quote:
Originally Posted by NoBandingPlz View Post
So you have an LE8500... and you don't see the horizontal banding on light, solid colors?

I have a laptop hooked up with HDMI and when I open a web browser... there are lots of spots where the screen is all white or another very light color and the horizontal banding is horrible... it seems like when you blink or move your head it has a sort of strobe effect. You don't get that on your tv? Or have you never looked at large, light colored areas on the screen?

I might be able to live with the banding on movies - but the kind of banding on the light, solid colored areas is just too much to take.
Yes I have a 55LE8500 and yes I have never seen banding on solid colors or static images. That said I have not connected a PC to it. My sources are DirecTV HD DVR, XBOX 360 and LG BD390.

I only see it on panning shots with gradual gradients in the background. Static scenes - or panning shots with solid colors are fine.

Edit: I should add I have used AVSHD, Spears and Munsil and Disney WOW calibration disks and have never seen the banding on any of the test patterns (which include many with solid colors) or the demonstration clips. The Spears and Munsil clip seems particularly demanding but looks great. Similarly the Disney WOW movie clips (mainly animation - but including Pirates of the Caribbean and Illusionist) also do not show any banding. It is a puzzle why some material seems to cause the banding - but others don't.
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post #9 of 21 Old 12-31-2010, 07:52 AM
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Quote:
Originally Posted by undecided View Post

Algorithms can be implemented in hardware or software - I still maintain I have never seen it on a solid color or static image - have you?

I don't have first hand experience with either of the LE8500 or LE9500, but it's apparently there according to NoBandingPlz.

I just don't understand why you can't accept my reasoning
Algorithm or not, that does NOT explain the horizontal banding whatsoever.
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post #10 of 21 Old 12-31-2010, 10:27 AM - Thread Starter
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The signal from the laptop is otherwise great on still images... but on light, solid colors - it's just really bad... it's the worst with white or similar shades... but also on light shades of green, purple etc. you can see it too.

Can you create some light colored images and load them via the USB... and really try and see if there is any horizontal banding on them - because this is the reason I'm returning the TV... but, I really don't want to have to go through that.

To note: I really can't believe that a TV of this caliber would have such horrible banding like this... so I'm hoping I can fix it somehow.
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post #11 of 21 Old 12-31-2010, 01:35 PM - Thread Starter
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Quote:
Originally Posted by Do-It-Yourself View Post

I don't have first hand experience with either of the LE8500 or LE9500, but it's apparently there according to NoBandingPlz.

I just don't understand why you can't accept my reasoning
Algorithm or not, that does NOT explain the horizontal banding whatsoever.

Create some large white jpg files and view them from the USB port... and you will see the horizontal banding issue... IT'S HORRIBLE... you have to look at the tv for a while - because if you just glance you won't see it... I don't know - but the longer you look... you can see flickering little horizontal waves or ripples... try out the jpg images and you will see it, I know it's not my signal causing it.
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post #12 of 21 Old 12-31-2010, 03:46 PM
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Quote:
Originally Posted by Do-It-Yourself View Post

I don't have first hand experience with either of the LE8500 or LE9500, but it's apparently there according to NoBandingPlz.

I just don't understand why you can't accept my reasoning
Algorithm or not, that does NOT explain the horizontal banding whatsoever.

Sorry I don't understand the reasoning. I see vertical banding on horizontal pans and horizontal banding on vertical pans - don't see what they couldn't be caused by local dimming algorithms............
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post #13 of 21 Old 12-31-2010, 03:48 PM
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Quote:
Originally Posted by NoBandingPlz View Post

The signal from the laptop is otherwise great on still images... but on light, solid colors - it's just really bad... it's the worst with white or similar shades... but also on light shades of green, purple etc. you can see it too.

Can you create some light colored images and load them via the USB... and really try and see if there is any horizontal banding on them - because this is the reason I'm returning the TV... but, I really don't want to have to go through that.

To note: I really can't believe that a TV of this caliber would have such horrible banding like this... so I'm hoping I can fix it somehow.

I'll try and put some on a USB and see - but again I use test patterns from Calibration Blu-Rays with solid white (or other solid colors) I don't see it.
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post #14 of 21 Old 12-31-2010, 05:17 PM - Thread Starter
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Originally Posted by undecided View Post

I'll try and put some on a USB and see - but again I use test patterns from Calibration Blu-Rays with solid white (or other solid colors) I don't see it.

If you sit completely still and don't move your eyes... all you will see are faint blackish, horizontal waves... but if you move your eyes up and down... going from the top of the tv to the bottom.... those lines will start to flicker/strobe really bad.

I don't see how this could be normal - it's just so horrible... I wouldn't expect this on a cheap LCD screen.... what the hell is going on here!
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post #15 of 21 Old 12-31-2010, 05:33 PM
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-sigh-

Alright, I'm done here. I've explained the cause of problem.
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post #16 of 21 Old 01-01-2011, 01:54 PM
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Originally Posted by Do-It-Yourself View Post

-sigh-

Alright, I'm done here. I've explained the cause of problem.

OK - humor me - maybe I am slow. I have read your description above. I still don't get why panning images bring out this issue. Horizontal pans - vertical banding. Vertical panning - horizontal banding.

If you can explain in more detail maybe I'll get it - my Physics BSc is a distant memory but some of the brain cells still work.

It sounds like the 55" has 1200 LEDs with 240 addressable segments (zones)

http://www.digitalone.com.sg/reviews/article/784
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post #17 of 21 Old 01-01-2011, 04:04 PM
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Quote:
Originally Posted by NoBandingPlz View Post

If you sit completely still and don't move your eyes... all you will see are faint blackish, horizontal waves... but if you move your eyes up and down... going from the top of the tv to the bottom.... those lines will start to flicker/strobe really bad.

I don't see how this could be normal - it's just so horrible... I wouldn't expect this on a cheap LCD screen.... what the hell is going on here!

So I took this image http://www.pbase.com/jackcnd/image/64242808 (solid white 1080P) put it on a USB.

I can see no banding at all. I have tried moving my eyes, head etc. Maybe I am not susceptible the effect you see. I am sitting about 8 ft from a 55LE8500.

I do definitely see banding on panning screens - but as I said before I have never seen it on a static screen.
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post #18 of 21 Old 01-01-2011, 04:31 PM - Thread Starter
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Originally Posted by undecided View Post

So I took this image http://www.pbase.com/jackcnd/image/64242808 (solid white 1080P) put it on a USB.

I can see no banding at all. I have tried moving my eyes, head etc. Maybe I am not susceptible the effect you see. I am sitting about 8 ft from a 55LE8500.

I do definitely see banding on panning screens - but as I said before I have never seen it on a static screen.

Hmmm. I wonder - because I see these horizontal bands more and more... it's really bad... I mean, I don't think this could be normal for such a pricey and well reviewed tv... but it really doesn't seem like the tv is "broken" in anyway.... I get the waves via hdmi, usb and now RGB PC port...

I don't think I could be more dissatisfied with this tv... and I REALLY want to like it.

It's horrible on my eyes. It's painful to sit here and try to look at a white screen.

I can't believe I have to return this big ass thing!!!!!!!!!!!!!

I gave LG a try and that's the last time... they failed to deliver the goods. I'll go with Samsung or Panasonic next. Pray that I get a good t.v. this time!

P.S. I think I already said this - but I've never seen a t.v. that had banding issues this bad... I'm dumbfounded.
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post #19 of 21 Old 01-02-2011, 02:14 PM - Thread Starter
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Read this: http://www.avsforum.com/avs-vb/showt...2#post18882262 - identical problem to what I described.
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post #20 of 21 Old 01-02-2011, 08:00 PM - Thread Starter
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Here's another person describing the exact same problem:

"These sets do seem to have a screen uniformity issue. Large and bright, white or very light colored sections of the screen will show light horizontal bands. These bands are light, but can be distracting depending on the viewer. It seemed to get better with more hours on the first set, but it could have been the firmware issue. Either way, know that if you watch a lot of content containing mostly white screens, you may want to look at another TV."

http://dlp4.com/lg-infinia-55le8500-...lications.html
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post #21 of 21 Old 01-02-2011, 09:09 PM
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The reason for the banding is also the reason LG can make the panel so thin, yet still back lit. The LEDs are placed extremely close to the LCD panel, which means each LED ends up lighting a very small "spot" of the screen. LG then added a diffuser layer in front of the LEDs to "spread" the light to a larger area to fully cover the screen. The problem is no diffuser can be 100% uniform, especially given the manufacturing tolerances for consumer products. As a result we get the banding problem, which I surmise roughly aligns with the edges of the diffusion zones.

On a static image, the bands are DEFINITELY visible, especially on a panel that has some operating hours on it, as the local dimming also causes asymmetric ageing of the LEDs and starts to exaggerate the differences between the zones. On my LX9500 with about 500 hrs, the vertical bands are starting to become more visible.

This is a hardware problem, and LG has changed the design of their diffuser to address the issue in their upcoming LEX8 line. However, I have found that if local dimming is disabled, I notice the banding much less. My guess is that the dimming action tends to further exaggerate the difference in the zones, especially on panning shots.


The HX909 is a nice set, and it has no banding, but it is also much thicker than the LE8500/LX9500, and the OptiContrast panel casts a bluish hue to everything, even the black. I felt the colors looked a lot more natural on the LG sets and the reflections weren't a concern for me. The LX9500 was also 1k cheaper, which is a big enough difference for me to ignore the banding.

HTH.
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