AVS Forum banner

Status
Not open for further replies.
1 - 9 of 9 Posts

·
Registered
Joined
·
219 Posts
Discussion Starter · #1 ·
I've been noticing more banding (solarization, posterization, pick your favorite term) on my panasonic 50PHD6UY. I used Avia and DVE to set it up. I'm not sure I've got it tuned correctly. Anyway, it is very noticable on a couple of DVDs. The very start of the following movies: light bulb scene of Six Sense, opening clouds of Harry Potter and opening clouds of treasure planet (chapter 1, time 0:05 type of stuff). Are these problems with the DVD transfers, the plasma panel, or set up? What are the most effective parameters to tweak to improve/minimize this problem? Black level and gamma don't seem to have an effect. I've got the plasma connected via component to the rcvr. dvd player component to rcvr.


thanks for your thoughts,

Dan Q

50PHD6UY

Denon 3803 AV RCVR

Denon 910 DVD

Moto 5100 comcast HDCABLE
 

·
Registered
Joined
·
35 Posts
Dan,


I recently purchased a 50PHDUY and think I am experiencing the same problem. Mine only seems to do it with totally black scenes. It also shows up in the letter box blocks on the top and bottom of screen (so I ruled out the DVD player). I haven't been able to play around with it that much and plan on getting it calibrated by an ISF tech. I believe this is partially due to the fact that we're sending it SD signals. I am sending everything directly to the display from my DVD/DBS via SVHS or component. I can't get my colors perfect, but hope that gets resolved by the tech as well. The black extension seems to help.
 

·
Registered
Joined
·
1,315 Posts
I have a 42PHD6UY arriving Friday. If it displays this problem, it will a significant disappointment. The Costco Pio 4310 (433CMX relative) I now have has minimal banding problems, and it is only a 256 shade, 16.7 million color display. The new Panny is somewhere over 1024 shade 1.07 billion color display, so banding SHOULD be essentially absent. Dark scenes present more of a challenge in this regard, but I was hopeful this would be a non-issue. I saw a head-to-head of a 5UY versus a Fuji 30WS and the Fuji showed far less banding.


There is a scene in Coral Reef Adventure in which an expanse of blue ocean surface viewed from underwater produces banding on the Pio but not on my PC CRT. I have seen comments by others that banding is inherent in plasma sets, but my graphics hardware background tells me banding reflects inadequate color depth, which I was banking on being alleviated by the new Panny's big color numbers.


I don't know if this can be adjusted out. Some suggest reducing contrast helps. Not for me and the Pio. A thread here on the Akai 4294, which displays pretty awful banding out of the box, describes some success with some advanced service menu adjustments, although it appears these may introduce other anomalies. Maybe a calibrator snooping here can tell us whether banding can be resolved.


Bill
 

·
Registered
Joined
·
361 Posts
I have the Panny TH-42PWD6UY (Mfg. date 11/03). I have noticed significant banding on SD programming from satellite feeds, especially on the more highly compressed channels. Bright blue backgrounds seem to be the most affected.


I cannot recall noticing any banding on DVDs.


My satellite receiver is connected via composite, and my DVD player is connected via component.


I am assuming, based on my observations with my system, that the banding issue is a by-product of poor video signals. In other words... the better the signal, the less chance of banding. On highly compressed channels, the plasma has less video information to work with, and therefore, picture anomalies become visible. When feeding the plasma a strong signal, such as a DVD which contains more video information for the plasma to work with, banding is much less noticeable.


This is just my theory, but based on my personal experience, it seems to make sense.


Pilot
 

·
Registered
Joined
·
206 Posts
I found that setting gamma at 2.5 helped. Also, I used a horizontal gray ramp in Avia to adjust brightness and contrast until the ramp was as smooth as possible and as even as possible. I adjusted until the black on the right was as dark as possible without getting wider and did the same with the white on the right. This got rid of most of it. I suspect another contributor is certain colors being pushed at certain levels. I bet a good calibration would make it even better.


BTW, I had seen this problem even with HD sources.
 

·
Registered
Joined
·
8,948 Posts
Anyone have a picture to post so I can see what this looks like? And is it really caused by the display or by the source/cables? Some people say composite (vs S-video) connections work better on Panny plasmas - have you tried that?


Dsmith
 

·
Registered
Joined
·
549 Posts
Quote:
Originally posted by DanQ
I've been noticing more banding (solarization, posterization, pick your favorite term) on my panasonic 50PHD6UY. (...) opening clouds of Harry Potter
Second that, same DVD. The first few seconds of the first scene (the "Privet Drive" sign) looked really bad on my Panasonic TH-42PWD6UY. Ok, it's a dark scene, but the wide bands of exact same colors coming from the left bottom corner while camera pans are much too obviuos.


I actually used to put blame (partially) on the below-standard quality of this particular DVD transfer, and (mostly) on my cheapo DVD player, AKAI DVPS760, hooked up via component, progressive mode. I thought my player simply has not enough horse power with its 27 MHz/10-bit DAC and probably an inferior MPEG decoder.


Since your player, Denon 910 DVD, is much better and still has the banding.. this makes me think again. I'm expecting delivery of Panasonic RP62 (hopefully the older one with the Faroudja deinterlacer) beginnig of next week, so I'll do some comparison.
 

·
Registered
Joined
·
127 Posts
I am curious if anyone can agree with my thoughts on this issue. I see some banding on my JVC 42WX84 HD plasma.


It "normally" appears in background scenes of compressed quality feeds (whether DVD or SD or Cable) where dark/light contrast exists in a panning screen shot. Also, since the tight focus of the shot is usually in the forefront of the image (i.e, faces/images) versus the rear of the scene which is out of focus by design, the low light and/or compression make it difficult (impossible) for any plasma to not show some level of banding. In this case you have low light/contrast and no detail in the background for the plasma to delineate a sharper image. You see what it sees, basically similar colored blocks of pixels blended by the compression.


I can't recall ever seeing this on a really good HD feed.


Is it the compressed image being fed to the plasma or is it the plasma?
 

·
Registered
Joined
·
549 Posts
Quote:
Originally posted by frawls1
(...) I see some banding on my JVC 42WX84 HD plasma.


It "normally" appears in background scenes of compressed quality feeds (whether DVD or SD or Cable) where dark/light contrast exists in a panning screen shot.
I'm not familiar with MPEG-2 compression algorithm. Is this situation (dark/light contrast present, and spatially extensive - 50+% of screen, dark backgorund with low color range) such a tough task for MPEG decoder? From top of my mind, it seems to me that decent decoder (or is it in post-decoding processing?) should have no problem interpolating colors in the low dynamic range part of the picture. Unless, of course, the bands of same color are what was encoded in the first place. Viewing the abovementioned first scene of "Harry Potter I" on PC, with software DVD player (it's WinDVD version 4 if I'm not mistaking) the banding still can be seen, but much less obvious. Darn... can't think of a simple way to check if the bands were actually encoded. Or rather can't think of any way to check it.

Quote:
Originally posted by frawls1


Also, since the tight focus of the shot is usually in the forefront of the image (i.e, faces/images) versus the rear of the scene which is out of focus by design, the low light and/or compression make it difficult (impossible) for any plasma to not show some level of banding. In this case you have low light/contrast and no detail in the background for the plasma to delineate a sharper image. (...)
Isn't this a job of a player - I mean, all the processing, not of plasma itself?

Quote:
Originally posted by frawls1


Is it the compressed image being fed to the plasma or is it the plasma?
I think the image fed to plasma is not compressed in any way.
 
1 - 9 of 9 Posts
Status
Not open for further replies.
Top