Panasonic 480hz sub field questions - Page 2 - AVS Forum | Home Theater Discussions And Reviews
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post #31 of 46 Old 01-23-2009, 08:41 AM
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Originally Posted by SM-65Atlas View Post

but I believe 480hz is the actual rate the pixels refresh at on Panno PDP's. The number divides well into current display standards, a Panasonic refreshes each frame of 24fps at twenty times per frame, broadcast TV at 16 times a frame, PS3 60hz motion comes out at eight times per frame and so on.

Technically this is correct. However, the panel still refreshes a fully composed frame only 60 times per second no matter what. When you say refresh you are talking about the subfield refresh frequency.

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PDP's having to refresh the pixels is why they burn more power and aren't quite as bright as LCD's, because for some fraction of each second they actually aren't emitting any light at all.

Yes and No. Fundamentally, the source of low brightness and high power is the poor energy efficiency when generating VUV. But you are correct that high refresh contributes to power consumption and short duty cycle contributes to low brightness.


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Originally Posted by SM-65Atlas View Post

This would explain Pioneer Kuro's excellent performance - and "72hz 3:3 pulldown" - if you assume the Pioneer's refresh is 720hz. It matches the AC line voltage (720/120=6), and all display modes. It also explains why Kuros have that awesome contrast. Since they refresh 60% more than the Panasonic, they would inherently be brighter if all other things are equal. Of course, you can take that brightness back down by using a very dark, high-contrasty filter in the screen, and changing the mix of the gas in the plasma cells to offer better color vs. absolute brightness, in addition to lowering the current-per-refresh. Of course Kuros are known for their unbeatable contrast and colors, and that I would guess is why.

Incorrect. Pioneer uses 840Hz or more (14 subfields). Kuro has excellent contrast because they have reduced the emission of light from the reset pulse to ultra low levels compared to pre-Kuro panels while at the same time boosting efficiency of VUV generation.

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Since they refresh 60% more than the Panasonic, they would inherently be brighter if all other things are equal

The opposite is generally true with Plasma. The more you refresh the less time there is to emit light.

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post #32 of 46 Old 01-23-2009, 12:18 PM
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Originally Posted by rgb32 View Post

Where did you find out/determine the >=840Hz subfield refresh stat?

I have a stack of Pioneer patents and technical papers that suggest so. The original "CLEAR" driving that pioneer used in the late 90's suggest that they have used 14 subfields from the beginning. However, you never know what exactly is in a product (except Pioneer engineers and D-Nice )

Here is a graphic for you....


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post #33 of 46 Old 03-31-2009, 08:36 PM
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Salespeople don't just lie because they're untrained and low-paid. It's a necessary part of selling: to say whatever to make a sale. And I do mean 'whatever'. I've known a few store owners who were well paid, in the same business for 20 years, and went to all the CES shows, even the ones in Japan. All they ever picked up from these shows was jargon and bits of misinformation. And then, these guys would tell customers the same lies for so many years, they don't even realize they're lies!
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post #34 of 46 Old 05-13-2009, 08:13 AM
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Would that graphic be correct? Assuming its 5 subframes and 50hz base-frequency. Red / Green are the two Frames to be shown consecutive.
Or do single pixels get refreshed like 8 Times per Frame? Above Image would mean 1 pixel > 1 refresh per frame but 5 partial refreshes per frame.
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post #35 of 46 Old 05-13-2009, 09:03 AM
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Originally Posted by zapl View Post


Would that graphic be correct? Assuming its 5 subframes and 50hz base-frequency. Red / Green are the two Frames to be shown consecutive.
Or do single pixels get refreshed like 8 Times per Frame? Above Image would mean 1 pixel > 1 refresh per frame but 5 partial refreshes per frame.

If I understand correctly you are trying to show that the displayed red frame is built up over 5 subframes (subfields) which is correct. However, the green background in those subframes should be black and the last subframe should not be a solid color of red. In reality there is no halftoning on a single pixel level as you have shown but I understand what you are describing. It is the combination of all the subframes that forms the solid red color on our eyes.

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post #36 of 46 Old 05-13-2009, 11:41 AM
 
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Regardless of "subfields" last years plasmas including the Pioneer generate about 900 lines of motion resolution on test patterns. This years new plasma TV's from all companies(Samsung,LG,Panasonic etc) are capable of producing the full 1080 lines of resolution on the same test patterns. The new Plasmas are all 600hz subfield processing units(and some of these 600hz sets do 24p content via 4:4/96hz instead of 3:3/72hz like the Pioneer does), so there is more to refresh rate than subfield performance.
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post #37 of 46 Old 05-13-2009, 12:12 PM
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Originally Posted by ZippyBongHitsWee View Post

Regardless of "subfields" last years plasmas including the Pioneer generate about 900 lines of motion resolution on test patterns.

Corection.... Over 900 lines of resolution.

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The new Plasmas are all 600hz subfield processing units(and some of these 600hz sets do 24p content via 4:4/96hz instead of 3:3/72hz like the Pioneer does), so there is more to refresh rate than subfield performance.

Well if you want to play the subfield game, Pioneer is 840Hz and has been like that for 2 generations. Subfieds and Hz are gimmicks on plasmas. They are now adding these gimmicks to plasmas to combat LCDs with their 120 and 240Hz marketing.
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post #38 of 46 Old 05-13-2009, 01:22 PM
 
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Quote:
Originally Posted by D-Nice View Post

Corection.... Over 900 lines of resolution.

Well if you want to play the subfield game, Pioneer is 840Hz and has been like that for 2 generations. Subfieds and Hz are gimmicks on plasmas. They are now adding these gimmicks to plasmas to combat LCDs with their 120 and 240Hz marketing.

That was my point.

As for the the motion test, using my FDP blu ray disc both the Pioneer 50 and 60" ELite screens score a solid 900 lines, not over, not under. Its solid at 900. My 11UK posts a solid 800 lines as does my 5054 Samsung. My newest Samsung though puts down a full 1080 lines. So does the new G series Pannasonic as well. And I understand the new LG's do also.

Sorry, the Pioneer Kuro, along with all the other models from years past are already starting to show their age to the newest generation plasma screens whether you like it or not.
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post #39 of 46 Old 05-13-2009, 01:30 PM
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Dude, you need to get the "D-Nice is defending Pioneer" ideology out of your head. I'm not. I'm just correcting points I know are wrong based on MY tests. If you really think you can see a difference on BD/DVD/Cable/Sat content between 800 lines of resolution and 1080 lines of resolution with fast moving scenes, you are holding true to your user name Zippy Bong Hit and then you go Weeeee.


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That was my point.

As for the the motion test, using my FDP blu ray disc both the Pioneer 50 and 60" ELite screens score a solid 900 lines, not over, not under. Its solid at 900. My 11UK posts a solid 800 lines as does my 5054 Samsung. My newest Samsung though puts down a full 1080 lines. So does the new G series Pannasonic as well. And I understand the new LG's do also.

Sorry, the Pioneer Kuro, along with all the other models from years past are already starting to show their age to the newest generation plasma screens whether you like it or not.

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post #40 of 46 Old 05-13-2009, 01:33 PM
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Quote:
Originally Posted by xrox View Post

However, the green background in those subframes should be black and the last subframe should not be a solid color of red. In reality there is no halftoning on a single pixel level as you have shown

Each square is meant to be the whole visible screen. The green pixels belong to the old frame, the red are part of the new. The dither was used to clarify my understanding of 'subfield' - if I am correct pixels of one subfield are scattered over the whole screen.
I hope thats still correct
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post #41 of 46 Old 05-13-2009, 02:11 PM
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Quote:
Originally Posted by zapl View Post

Each square is meant to be the whole visible screen. The green pixels belong to the old frame, the red are part of the new. The dither was used to clarify my understanding of 'subfield' - if I am correct pixels of one subfield are scattered over the whole screen.
I hope thats still correct

I think you understand just fine that Plasma displays must "compile" images from a set of sub-images (subfields).

But at the start of each and every subfield the entire screen is turned off (reset) and subfield pixel data is written again. That is why the background should be black in your graphic.

Also, dither and halftoning are used to create gray levels not otherwise possible by individual sub-pixels. Sub-"fields" are what determine how many gray levels each individual sub-pixel can generate itself.

For example: 8 subfields combined in a binary system can generate 256 gray levels without any dithering or halftoning.

That being said, your graphic should show 5 full screen, solid color, increasing gray levels of red without any dithering. And the actual image we percieve should be shown seperately as it is a combination of the 5 gray levels (5 subfields).

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post #42 of 46 Old 05-13-2009, 02:37 PM
 
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Originally Posted by D-Nice View Post

Dude, you need to get the "D-Nice is defending Pioneer" ideology out of your head. I'm not. I'm just correcting points I know are wrong based on MY tests. If you really think you can see a difference on BD/DVD/Cable/Sat content between 800 lines of resolution and 1080 lines of resolution with fast moving scenes, you are holding true to your user name Zippy Bong Hit and then you go Weeeee.


Just say no to drugs.

Actually some people can see the difference in how clear a screen can produce fast moving images, just like some people can see phospher lag, rainbows etc.

Since I am a big fan of sports, fast motion resolution to me is important. The difference between 900 and roughly 1100 lines isnt great, but its still a difference and some people can notice it. Just like shades of black, color etc. which many other people make a big deal out of(guess who? )
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post #43 of 46 Old 05-14-2009, 02:40 AM
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A lot of those people that see things that others dont are fooled by their own mind. (Selective perception) Seeing smother movement when it is advertised that you should see it is a good candidate for that Same goes for high quality HDMI cables and stuff.
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post #44 of 46 Old 05-19-2009, 12:17 AM
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Quote:
Originally Posted by xrox View Post


Here is a graphic for you....


Interesting picture xrox !

Do you know if different subfields could be combined during a frame ?
Imagine I want a luminosity of 52 so I enable the subfield SF14 (which has a value of 39) and the subfield SF6 (which has a value of 13).

Or you can enable only one subfield during the complete frame ?

Another question : do you know if all the cells are synchronized ?
For example during the first 0.1 ms I can enable only the SF1 subfield of all the cells which need it, and after that and during 0.3ms I can enable only the SF2 etc.

Thanks
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post #45 of 46 Old 05-19-2009, 01:11 AM
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Subfields Can be on duty independently. You can use any combination of the above simultaneously. One reason why pioneer pushed for more subfield (>8 knowing 8bit is nough to present 256 level of grey) is to fight false countour effect since duty cycle spread more in time.
re your second question, each subfield span a fixed period of time.
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post #46 of 46 Old 10-05-2009, 01:15 PM
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Sorry for responding to such an old thread but I was doing a google search on subfield informantion and found this thread with an old question addressed to me and an incorrect response.

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Originally Posted by Lessard View Post

Do you know if different subfields could be combined during a frame ?Imagine I want a luminosity of 52 so I enable the subfield SF14 (which has a value of 39) and the subfield SF6 (which has a value of 13).

In the graphic above which is Pioneer C.L.E.A.R driving there is no possible way to only combine SF14 with SF6. With CLEAR driving the subfields must always be sequential (one after the other)

In Panasonics case, they use binary driving, which allows for non-sequential selection of sub-fields. In other words in Panasonics case, yes, they can combine whatever subfields they want.

Pioneer (CLEAR)
- subfields can "only" be sequential (one after another)
- subfield weights can be altered during operation
- 8 subfields = 8 gray levels for Pioneer

Panasonic (REAL BLACK)
- Any subfield combination is possible
- subfield weights cannot be altered
- 8 subfields = 256 gray levels for Panasonic


Quote:


= Another question : do you know if all the cells are synchronized ?
For example during the first 0.1 ms I can enable only the SF1 subfield of all the cells which need it, and after that and during 0.3ms I can enable only the SF2 etc.

In most cases, the subfield position in time never changes relative to other pixels. So yes they are always synchronized in time.

Exception : Pioneer "advanced CLEAR" driving uses a scan type display mode where several rows of pixels are addressed while others are displaying light. They do this in a CRT type line by line fashion.

Cheers

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