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Discussion Starter · #1 ·
I know this Samsung PS50B456B2W is not exactly fresh, but it has been doing this as far long as I can remember. I recently got myself an small Intel NUC as a HTPC, and GUIs and still images made me much more concious and troubled by this issue. Its appearance reminds of "signal distortion" or sparkling of some kind. Actually, sort of like looking really close in on a CRT screen.

It seems to be green pixels that are most pronounced, although this could be down to perceived color light. Adjustments to brightness, contrast, cell light etc - will take "take the color out" of these pixels. The phenomenon itself however, is still visibly there. Its not like when I previously had bad or too long HDMI cables - that would be horrible and visible from miles away. It isn't really much visible in very dark/black areas when there is picture/video - nor very visible in very bright/white areas. But you can tell its going on, even if clear white. If black - I guess its happening but you just can't see it.



I've read people suggesting adjusting Vsc voltage (down), but those instances have seemed to be mostly affected by green/red powerful sparkling / retention sparkling. This doesn't really seem to be actually related to any particular color... but I could be very wrong.

It does not seem to be more predominant on any particular area of the panel - its more dependent on what color or hue is displayed at any particular point

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Firmware is the newest sammy reported - 2010.09 something. This happens even with no connections to the TV, but the power cable (you van see it on the "check signal" blue-green box). TV is conected through a quality (component-wise) power filter.




I've got a few videos of this phenomenon, I'll try to upload them somehow.


The camera is fairly decent - the pixel artifacts seen here is not the camera, but the problem described.



NOTE: Videos was recorded in 1080p - if you choose any lower resolution in YouTube, compression will ruin the image so you won't be able to see the problem. HD fomats might take 10-30 minutes after post, to be available.


Showing a black/white test pattern:


While adjusting brightness/contrast:


Pardon my fiddling about, I'm no camera man. And the Vertical video, I'm really no camera man.
 

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Looks like someone went mad with spatial dithering
Quote:
This dithering method involves assigning appropriate colour values from the available colour palette to close-by pixels in such a way that it gives the impression of a new colour tone which otherwise could not have been created at all. In doing so, there complex mappings according to which the ground colours are mutually assigned, otherwise it could result in colour noise / dithering noise. Dithering can be used to allow 6-Bit panels, like TN Film, to show 16.2 million perceived colours. This can however sometimes be detectable to the user, and can result in chessboard like patterns being visible in some cases. Spatial dithering is rarely used in the modern market and instead Frame Rate Control is more widely utilised. ref


Tell me what happens when you load these image at full screen, does the noise freeze in some or most areas? (they are cropped to exact size of your screen 1360x768)



 

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Discussion Starter · #3 ·

Quote:
Originally Posted by ChadThunder  /t/1524421/samsung-ps50b456b2w-nois...s-of-input-or-basic-adjustments#post_24535428


Looks like someone went mad with spatial dithering

Tell me what happens when you load these image at full screen, does the noise freeze in some or most areas? (they are cropped to exact size of your screen 1360x768)

After viewing the images, it seems your indications could be right. It doesn't seem to completely "freeze" per say, atleast not everywhere - but the "noise" doesn't move around as it usually does. I don't know how to otherwise describe it - so I filmed it.


Sequence of "playback" (min 1080p view in Youtube):


XBMC background

Desktop

Posted image 3

Posted Image 1

Posted image 2

Desktop


Let me know if I need to do this one again, I'm not sure how well it reproduces due to camera angle, auto focusing etc. There is really a little bit (not much) more movement than I can see on the video here - but my computer display isn't 1080p so I can't know for 100% sure how it looks.


I've read up a little bit on Spatial dithering, I believe I understand its application. But, is this something I can do anything about? I had a little look through the service menu - but as I didn't notice anything I could interpret as a related setting, I left it untouched. Might be something there, I just don't know eaxtly what I'm looking for.

Please note: This is visible on the screen, even with nothing connected to it:
 

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Well that confirms the set is not faulty as in misfiring pixels, if was a Panasonic I would say put it in "cinema mode" and have a few tips to offer but you might have to eyeball it using just those images and another one I will post below as I can't find anything about your particular model




Things that exacerbate dithering are continuous tones and while its not defeatable you can tone it down by smoothing out the steps or "bands" in a gradient by using various controls like brightness, gamma, contrast and color gain, cutoff etc. . just work out whats acceptable to your eyes and try sit at the appropriate distance so it does not bother you
 

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Discussion Starter · #5 ·
Thank you for your help, I really appreciate this.


Either this worsened over the last 3-4 weeks, or it just really gnawed on my nerves and became a constant distraction. I was unable to ease this to an acceptable level, without "toning down" things so much that day-time viewing was no longer much doable.


Sold the set for a reasonable cheap buck (it is 5 years old and has seen heavy use over the years - also had a permanent burn-in at top corner). Bought a barely used Sharp Aquos LC60LE651E "smart" 3D TV for about £700, got £200 for the Samsung Plasma. I do miss the "movie'esqe" feel over plasma (light reflection on surfaces appear WAY different on LCD) - but I'm loving the bump to proper HD and the added 10 inches.


Without other changes to setup than resoultion to match new TV - I'm seeing "lagging blocks" when the image pans - or more pronounced when both the "subject" is moving and image is panning (camera and object moving in the same direction simultaniously (but NOT "in sync", the object does not stay in the same area of the overall image(!))) at the same time. The whole image is not skipping as as my early-age BluRay player might do in in panning scenes, its just "blocks" (e.g. the face and close proximity, of an actor that moves while camera pans simultaneously (object movement and camera panning not "in sync"), "the small houses" at the lower edge of the screen during Game of Thrones intro).


I'll see if I can't find something useful on this. Might be a well-known concept, but as I don't know what the phenomenon is called, I have problems finding anything useful. If I can't find anything soon, I'll open a thread on it. If you happen to be familiar with this phenomenon, you're most welcome to give me a pointer.


Probably already mentioned, but I use a computer running XBMC as my primary media source.
 
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