[PIC] Plasma Dithering - Is this normal?! - AVS Forum
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post #1 of 11 Old 08-05-2011, 06:30 PM - Thread Starter
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The dithering of grays on my new PN51D7000 has been REALLY bothering me. It's visible from my viewing distance of 7'. Very noticeable in dark scenes against widescreen black bars.

I finally went into Best Buy today and looked at a PN59D7000 up close and the dithering looks COMPLETELY different. On my screen, the flashing pixels are BRIGHT red/green/blue. On this floor model, the dithering was visible up close but the flashing pixels were all very MUTED in color, giving the appearance of actual gray.

Attached is a photo taken on the Disney WOW advanced contrast pattern of the +1% black. I think it clearly illustrates what I'm describing. On the PN59D7000 at BB, the dithering pixels had no where near this brightness or saturation.

Is my screen defective? Or is this another difference between the 51 and 59in models? I know the 59 is supposed to have darker blacks. I'm happy with the blacks... but not anything slightly lighter than black. And it seems most sources dont hit full video black (16), leaving me with this dithering mess against the likable black bars. Bright content looks great, and otherwise I'm happy with the PQ. Just this.... and the BUZZING

Thanks!
LL
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post #2 of 11 Old 08-05-2011, 06:38 PM
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if that is an accurate representation, it looks pretty terrible to me...

I'd request a swap asap
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post #3 of 11 Old 08-05-2011, 06:42 PM
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Dithering is normal, but that picture would concern me. From reading the post I got an impression that it's a difference of settings, but from that test pattern if a TV is displaying something black it should dither gray pixels.
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post #4 of 11 Old 08-05-2011, 06:47 PM
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I own two 2010 Panny plasmas. I found on both that the dithering was worse while the phosphors were breaking in. Once you get past 150 hours or so i found both my sets settled down. I found the dithering really bad on SD channels viewing something with hard lines.. like cartoons. With HD sources or blurays you shouldn't be seeing too much dithering. The Best Buy sets you looked at probably have a couple thousand hours on them, so until you get some serious hours on yours its really hard to compare that the two displays.

I have a 58VT25 and i sit about 9 feet from it. This set is 4 months old and I dont see the dithering anymore.

In case you didn't know, dithering is normal with plasmas.

Mike
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post #5 of 11 Old 08-05-2011, 08:18 PM
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Now that screenshot looks almost exactly like the dithering of near black areas look on my LG PK350 Plasma.
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post #6 of 11 Old 08-05-2011, 08:26 PM
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1% is supposed to be barely viewable from your seating area, and any close screenshot will show dithering. Turn down the brightness a bit. Perhaps I'm missing something.
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post #7 of 11 Old 08-05-2011, 08:49 PM
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Yes, that looks like plasma dither to me, though from a normal seating distance, 1% above zero black shouldn't be noticeable. That pic looks like exaggerated dither to me.
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post #8 of 11 Old 08-05-2011, 09:42 PM - Thread Starter
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Quote:
Originally Posted by tfoltz View Post

1% is supposed to be barely viewable from your seating area, and any close screenshot will show dithering. Turn down the brightness a bit. Perhaps I'm missing something.

Yes, it is adjusted to be just visible. The camera is slower than the 600hz subpixel refresh rate, so you could say it's a mini timelapse. Where in reality, not that many pixels are illuminated simultaneously in +1% black. But it is an accurate representation of the intensity/color of the flashing pixels in dark gray.

I was playing The Fountain and I Am Legend earlier, and the dark scenes are nearly unwatchable. So much of the screen hovers around +1% to +3% black, where the worse dithering occurs.

But than I just watched Rango (beautiful contrast), and I was thrilled with the pic quality and didn't notice any dithering at all.

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post #9 of 11 Old 08-06-2011, 12:32 AM
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I only notice dithering on my Panny ST30 if I have the brightness up higher than it should be. Your screenshot is what my TV does if i turn the brightness up too much. It took some getting used to. Coming from an LCD, I simply wasn't used to some stuff being that dark, and still having detail.

HTPC: I3 2100, Radeon 6950.
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post #10 of 11 Old 08-06-2011, 08:58 AM - Thread Starter
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Quote:
Originally Posted by ttnuagmada View Post

I only notice dithering on my Panny ST30 if I have the brightness up higher than it should be. Your screenshot is what my TV does if i turn the brightness up too much. It took some getting used to. Coming from an LCD, I simply wasn't used to some stuff being that dark, and still having detail.

My brightness is properly set. If I turn my brightness down even one more click, I start crushing blacks.
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post #11 of 11 Old 08-06-2011, 09:14 AM
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Quote:
Originally Posted by Raven Crimson View Post

Yes, that looks like plasma dither to me, though from a normal seating distance, 1% above zero black shouldn't be noticeable.

Sorry, but you're supposed to even see "17", the nearest shade to "16" (black).

The better your black level, the claerer you see that though.

Quote:
Originally Posted by ttnuagmada View Post

I only notice dithering on my Panny ST30 if I have the brightness up higher than it should be.

You connaot campare ypur panny with the pwm noise-beaviour near black from LGs and Samsung-Plasmas!

In fact, Panasonics pwn noise near black appear to be grey and the single noisefreckles are way much nearer in space to each other, cause Panasonicplasmas are able to show each pwm-noiseelement much darker for itself than LG and Samsung.

P.S.: A LCD-TV is also capable to show all shades near black, if calibrated properly. Also, your ST30 exagerate shadow detail through its gamma bump near black.

Quote:
Originally Posted by Skitals View Post

I was playing The Fountain and I Am Legend earlier, and the dark scenes are nearly unwatchable. So much of the screen hovers around +1% to +3% black, where the worse dithering occurs.

Yep, "The Fountain" is a mess with clumpy noise like tha.

Other examples:

1. Master and Commander

2. Number 9

3. The nightscenes of "Rob Roy"

4. The church in "James Ryan"

and some other flicks.
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