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-   -   Panasonic 480hz sub field questions (https://www.avsforum.com/forum/167-plasma-flat-panel-displays/1006091-panasonic-480hz-sub-field-questions.html)

MomboX 03-10-2008 05:18 PM

Well I am sitting over here at Circuit City and am looking at the 80u Panasonic here. It says it has a 480hz Sub Field Drive. Anyone know what this is? What it does? Is this the same thing as the 120hz we have been seeing all last year and what not? Is the 480 number just a marketing ploy or what?

Thanks!

Turlen 03-10-2008 06:32 PM

Quote:
Originally Posted by MomboX View Post

Well I am sitting over here at Circuit City and am looking at the 80u Panasonic here. It says it has a 480hz Sub Field Drive. Anyone know what this is? What it does? Is this the same thing as the 120hz we have been seeing all last year and what not? Is the 480 number just a marketing ploy or what?

Thanks!

I did a tad bit of looking when I purchased my 42PX80U. I determined that the 480hz sub field drive is meant for PAL standard. If you live in the US, this probably will do nothing for you since the US uses the NTSC standard.

This info isn't a 100% solid, but it was all I could find on this issue.

xmarine2847 03-23-2008 01:53 PM

From what I have read and can determine out of all of the technical jargon is that it has something to do with light transmittance through each pixel. It divides each pixel of a frame into sub-fields and puts them on a certain time axis where the light transmittance is varied across adjacent pixels to help alleviate flicker which, in turn helps alleviate motion blur and also helps with grayscale accuracy.

If I can find a layman's term "translation" I'd better understand, but this is just what I have come to find based on the information I've seen.

xrox 03-23-2008 08:09 PM

Quote:
Originally Posted by MomboX View Post

Well I am sitting over here at Circuit City and am looking at the 80u Panasonic here. It says it has a 480hz Sub Field Drive. Anyone know what this is? What it does? Is this the same thing as the 120hz we have been seeing all last year and what not? Is the 480 number just a marketing ploy or what?

Thanks!

8 subfields per frame x 60 frames per second = 480 subfields per second = 480hz = Marketing jargon to compete with LCD 120Hz

xmarine2847 03-29-2008 12:59 PM

Quote:
Originally Posted by xrox View Post

8 subfields per frame x 60 frames per second = 480 subfields per second = 480hz = Marketing jargon to compete with LCD 120Hz

Not sure how accurate that is - but I'll find out very soon.

D-Nice 03-29-2008 06:57 PM

Quote:
Originally Posted by xmarine2847 View Post

Not sure how accurate that is - but I'll find out very soon.

It's very accurate. This isn't a LCD.

xmarine2847 03-29-2008 09:53 PM

Quote:
Originally Posted by D-Nice View Post

It's very accurate. This isn't a LCD.

Sources?

I'm quite aware this isn't LCD. However, I'm also quite convinced that the
"480Hz subfield drive" has little if nothing to do w/ comparison to LCD 120Hz framerates.
The question is... what is it, not what isn't it? Does it decrease flicker between adjacent pixels? Does it correct for phosphor lag? Does it balance your checkbook?

I have had minimal experience with the 80u, but the framerate - still 60Hz from what I can tell. Of course, this was before it's market release and was a prototype, so changes could have been implemented before final shipping. So if you have better sources and can explain your "it's very accurate" statement, I'm definitely interested.

cjm7c 03-29-2008 10:11 PM

Quote:
Originally Posted by xmarine2847 View Post

Sources?

I'm quite aware this isn't LCD. However, I'm also quite convinced that the
"480Hz subfield drive" has little if nothing to do w/ comparison to LCD 120Hz framerates.
The question is... what is it, not what isn't it? Does it decrease flicker between adjacent pixels? Does it correct for phosphor lag? Does it balance your checkbook?

I have had minimal experience with the 80u, but the framerate - still 60Hz from what I can tell. Of course, this was before it's market release and was a prototype, so changes could have been implemented before final shipping. So if you have better sources and can explain your "it's very accurate" statement, I'm definitely interested.

The frame rate is still 60Hz. What xrox and D-Nice were trying to say was that the subfields are refreshed at 480 Hz. This number is used to compete with 120 Hz LCDs even though its not directly comparable.

D-Nice 03-30-2008 11:17 AM

Quote:
Originally Posted by xmarine2847 View Post

Sources?

I'm quite aware this isn't LCD. However, I'm also quite convinced that the
"480Hz subfield drive" has little if nothing to do w/ comparison to LCD 120Hz framerates.
The question is... what is it, not what isn't it? Does it decrease flicker between adjacent pixels? Does it correct for phosphor lag? Does it balance your checkbook?

I have had minimal experience with the 80u, but the framerate - still 60Hz from what I can tell. Of course, this was before it's market release and was a prototype, so changes could have been implemented before final shipping. So if you have better sources and can explain your "it's very accurate" statement, I'm definitely interested.

Your answer lies in how plasmas display pictures. Try googling how a plasma works.

xmarine2847 03-30-2008 03:16 PM

Quote:
Originally Posted by D-Nice View Post

Your answer lies in how plasmas display pictures. Try googling how a plasma works.

Okay, I think I'm getting it. All this searching and reading is confusing beyond necessity. So the subfield drive method is actually something that's present in all PDPs and is nothing new? And you're saying that they've begun listing this specification, however irrelevant, as a comparison to 120Hz LCDs - probably true. In that case, however, to anyone who understand the terminology - isn't 480Hz kind of low-end?

xrox 03-30-2008 03:19 PM

Quote:
Originally Posted by xmarine2847 View Post

So the subfield drive method is actually something that's present in all PDPs and is nothing new? And you're saying that they've begun listing this specification, however irrelevant, as a comparison to 120Hz LCDs - probably true. In that case, however, to anyone who understand the terminology - isn't 480Hz kind of low-end?

Yes, Yes, and Yes.

dontbugme 04-16-2008 08:36 AM

"480H[z] sub field is for 24fps video."
- http://www.highdefforum.com/showthread.php?p=577160

"480 Hz refers to the subfield drive. 8 subfields per frame x 60 frames per second = 480 subfields per second = 480hz (A subfield drive system detects a PAL source and increases the number of subfields in a frame in order to reduce flicker.)"
- http://www.highdefforum.com/showthread.php?p=577160

"480Hz sub field drive: 480Hz sub field drive ensures that even fast action retains the highest possible resolution with no motion blur."
- http://www.circuitcity.com/ssm/Panas...oductDetail.do

"Plasma employs a system called sub-field drive which can be eight to twelve scans per field depending on the set. Also Panasonic use dual scan progressive technology, which in effect splits the screen in two vertically, and scans both parts [simultaneously]."
- http://www.avforums.com/forums/showthread.php?t=19354

I'm just acting as the medium - if any information here is incorrect, don't shoot the messenger.

David Susilo 07-08-2008 12:56 PM

so... what is the definite answer to the 480Hz sub-field drive question?

oakguy2000 08-01-2008 02:22 PM

If you read the review of the 50PZ850U on cnet, they mention that the 800U and 850U have a 48Hz mode for 24p support, which is NOT the case with the 80U and 85U. Also, if you look at the product specs at Panasonic.com, the two more expensive Panasonics are listed with '24p cinematic playback' but the 80u and 85u are listed just with 24p (3:2) playback. The cnet review also says the is an annoying flicker with the 24p 48Hz playback, so Panasonic is going to have to work on that feature some... the 85U still has a great picture and is way cheaper than the 850U, but doesn't have 24p native support.

Hard to find a definitive answer on what exactly the subfield drive does, but if I had to make a guess, hitting the pixel 8 times per frame should display a more flicker free picture because the phosphors in each pixel decay on the order of 10-100 microseconds, so hitting the pixel at 60Hz would mean there is an awful lot of time the pixel is dark. NO idea if any processing happens to interpolate anything at 480Hz.

It's a pretty misleading way of marketing the TV, since I doubt many salespeople will know that is had nothing to do with 120Hz LCD's and 24p playback, but they will compare and say 480Hz > 120Hz!!

xrox 08-01-2008 02:49 PM

Quote:
Originally Posted by oakguy2000 View Post

Hard to find a definitive answer on what exactly the subfield drive does, but if I had to make a guess, hitting the pixel 8 times per frame should display a more flicker free picture because the phosphors in each pixel decay on the order of 10-100 microseconds, so hitting the pixel at 60Hz would mean there is an awful lot of time the pixel is dark. NO idea if any processing happens to interpolate anything at 480Hz.

What exactly are you looking for as an answer? If you review this thread, "What 480Hz subfield drive is/does" has been answered. Regarding flicker, plasma displays flicker due to the effective duty cycle being ~35%.

Quote:
Originally Posted by oakguy2000 View Post

It's a pretty misleading way of marketing the TV, since I doubt many salespeople will know that is had nothing to do with 120Hz LCD's and 24p playback, but they will compare and say 480Hz > 120Hz!!

I agree that probable intentions are misleading regarding 480Hz, however at least they don't blatently lie. The panel is actually refreshing at 480Hz.

lhsjazzman 08-17-2008 09:12 PM

Hello all, this is my first post. I was reviewing this thread because this issue isn't as cut and dry as it should be. I was chatting with our Panasonic rep, who had just returned from a training session over the weekend. She showed me some paperwork she was given by her people.
Paraphrasing what she showed me:
The technology is a direct assault on 120 Hz. Yes, it's 480 Hz sub-field like we've discussed, but more importantly, it leverages the "vast processing power" of their processor. The processor is doing what they call, "Intelligent Frame Creation." hxxp://www.panasonic.com.my/web/Pid/5459 (I cannot post direct url, yet, sorry.

Their wording would lead one to believe it's somehow interpolating like the 120-Hz Samsungs and Sonys (Sharp 82 and Mitsubishi 144 models merely increasing their flicker rate - like projectors, and thus never looking as smooth), but they don't say this. The briefing she has says the processor analyzes frame by frame to maximize clarity... I looked at this quickly because it was lunch-time. I'll see if I can get her to get me a copy of this and I'll repost with their exact phrasing.

Anyway, just wanted to post this since I've been trying to peel more info out of her. I have to say, in side by side comparison, the th50pz800u looks much more natural to me than the ln52a750. The 750 made all the special effects segments of several of my favorite blu-rays look unbelievable (not in the good way). Our demo disk from Pan also has a few scrolling-marques which look much better on the 80 and 800s than my th50pz77u, which I still love!

xrox 08-18-2008 08:01 AM

Quote:
Originally Posted by lhsjazzman View Post

Hello all, this is my first post. I was reviewing this thread because this issue isn't as cut and dry as it should be. I was chatting with our Panasonic rep, who had just returned from a training session over the weekend. She showed me some paperwork she was given by her people.
Paraphrasing what she showed me:
The technology is a direct assault on 120 Hz. Yes, it's 480 Hz sub-field like we've discussed, but more importantly, it leverages the "vast processing power" of their processor. The processor is doing what they call, "Intelligent Frame Creation." hxxp://www.panasonic.com.my/web/Pid/5459 (I cannot post direct url, yet, sorry.

Their wording would lead one to believe it's somehow interpolating like the 120-Hz Samsungs and Sonys (Sharp 82 and Mitsubishi 144 models merely increasing their flicker rate - like projectors, and thus never looking as smooth), but they don't say this. The briefing she has says the processor analyzes frame by frame to maximize clarity... I looked at this quickly because it was lunch-time. I'll see if I can get her to get me a copy of this and I'll repost with their exact phrasing.

If I'm not mistaken, ifc (intelligent frame creation) is a 50Hz to 60Hz conversion using interpolation. 480Hz is simply a marketing creation out of standard plasma operating procedure. The only thing new about it is that they are using it in marketing. And IMO this is to combat the "120Hz" marketing of LCDs. After a quick google search it seems the description I gave in post #4 seems to match Panasonics description.

http://www.panasonic.ca/english/audi...sma/viera2.asp

xrox 08-18-2008 08:09 AM

Also note that if Pioneer was to use the same marketing they could claim 840Hz since they use 14 subfields

lhsjazzman 08-18-2008 09:44 PM

I don't disagree, I'm just trying to get the truth. We all know reps don't always know that much, which is why I'm curious if anybody has run image tests (HQV suite?) on the TV to see what it's doing. All I know is if it was a form of interpolation like the LCD processors use, I would expect similar visual incongruities. I just don't see the "artificiality" that LCDs show, so I'm kind of at a loss.

MikeySirkus 09-08-2008 02:42 PM

Well like all of you 480Hz was just too good to be true but once i seen the sub text underneath the large number display (advetisement) "Sub-Field Drive" I knew they were pulling my leg. I asked one of the store clerks working the floor and i wont say which store but it was a major "red" one and he confidently said "It's the refresh rate of the new Plasmas which is way, and he stressed "way", better than the 120Hz LCD models." he also went on and on just really trying to convice me and to sell me the TV. Dont get me wrong i see the differences but some of these employees have no idea what they're talkn about when they're trying to market these TVs I'm just looking out for the customer. all they know is what they read in there stores own advertisement.

David Susilo 09-08-2008 02:55 PM

Quote:
Originally Posted by MikeySirkus View Post

...and he stressed "way", better than the 120Hz LCD models."

in his defense, it is true that the plasma is way better than any 120 hz LCD models... but because it's a plasma and nothing to do with the 480Hz sub-field drive.

shagnat 09-18-2008 09:57 PM

Quote:
Originally Posted by MikeySirkus View Post

Well like all of you 480Hz was just too good to be true but once i seen the sub text underneath the large number display (advetisement) "Sub-Field Drive" I knew they were pulling my leg. I asked one of the store clerks working the floor and i wont say which store but it was a major "red" one and he confidently said "It's the refresh rate of the new Plasmas which is way, and he stressed "way", better than the 120Hz LCD models." he also went on and on just really trying to convice me and to sell me the TV. Dont get me wrong i see the differences but some of these employees have no idea what they're talkn about when they're trying to market these TVs I'm just looking out for the customer. all they know is what they read in there stores own advertisement.

I think I went to the same store and had the same clerk many years ago. It was so funny. I was perusing their massive selection of TVs and the clerk kept emphasizing "flat square tube" (yes, that long ago). After several times of pushing "flat square tube" down the customer's throat, the customer finally asked, "what's so great about FST?"...... the clerk responded "Because we see "flat" when we watch TV"
I almost lost it right then and there. Needless to say, I immediately left the store and have never made a significant purchase from them sense.
It's sad these big box stores pay their clerks so little and give them very little real training regarding knowledge. BUT, they sure know how to train them to sell their "extended warranty" package. LOL

cyiton 09-30-2008 09:09 AM

If anyone's question wasn't answered above, I believe this is the patent info:

.patentstorm.us/patents/7050035/claims.html

^ add the usual world wide web stuff in front, I can't post links yet

CosmoNut 10-01-2008 09:47 AM

I have a TV with this feature (the 85U, actually) and it's interesting to quickly flick your eyes left and right across the screen -- especially during movies. You kind of get that residual RGB effect that many DLP projector images have, but it's even more subtle. I imagine the phenomenon has something to do with the 480HZ sub-field processing.

coltsfreak18 10-01-2008 01:25 PM

Quote:
Originally Posted by CosmoNut View Post

I have a TV with this feature (the 85U, actually) and it's interesting to quickly flick your eyes left and right across the screen -- especially during movies. You kind of get that residual RGB effect that many DLP projector images have, but it's even more subtle. I imagine the phenomenon has something to do with the 480HZ sub-field processing.

No, that is phosphor lag, which is because some colors (yellow-green, I think) decay faster than others (red?)

pcdoh 11-30-2008 03:08 PM

First time poster, so if I should post this as a new post, pls let me know.

This is relative subject to my new search for an HDTV. Interested in a 46",
which will be in a windowless area. I do not like ghosting or blurs in action scenes, and desire vibrant colors. BB salesman told me, "you want a plasma."
Cited the 480hz vs LCD's 120hz. My SIL told me LCD is better.
So, what do I select? Is Pioneer a better plasma than Panasonic? tnx

David Susilo 11-30-2008 03:16 PM

1. yes plasma always trumps LCD for viewing angle, no lag, black level, you know... all the stuff that's actually important in viewing a movie
2. plasma can always be tweaked to give punchy colours... if you're into the wrong colour space and saturation.
3. Pioneer doesn't do 46". Get the next best thing: Panasonic
4. your SIL knows nothing about LCD vs plasma

SM-65Atlas 12-13-2008 02:10 PM

This is my first post and I just registered to post this. I was researching TV's and Google'ed 480hz to learn more about it, and this thread got me thinking...

"480hz" is just a marketing gimmick to counter the 120Hz LCD craze, 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. 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. They also need the refresh number to correspond with the line AC voltage without needing expensive electronics (60hz, ironically) to perform essentially a "pulldown" compensation with the incoming voltage.

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.

Blackraven 01-23-2009 06:09 AM

That sounds interesting (probably similar to JVC and their Clear Motion Drive whatever they call it thingy).

rgb32 01-23-2009 08:32 AM

It appears that the subfield drive of a plasma is related to how many times per second that each sub pixel (RGB) is charged to display the requested color (as it applies to Pulse Width Modulation). With the new 600Hz NeoPDPs, that may translate to 10 charges for each pixel when displaying a 60Hz source.

It definitely seems like the 480Hz spec of "how PDP works" has been used as marketing spew, since it isn't directly related to the frame interpolators used in most LCDs today...

My only hope is that the phosphors in the NeoPDPs (and hopefully '09 Pios) greatly reduce the RG/B difference...


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