Do PDPs output multiple refresh rates unlike LCDs? - AVS Forum
Plasma Flat Panel Displays > Do PDPs output multiple refresh rates unlike LCDs?
el pablo's Avatar el pablo 04:46 PM 05-04-2014
I know that LCDs refresh rate outputs are fixed i.e. a 120hz unit with always output at 120hz despite being fed a 24, 30, or 60hz signal

It seems this wouldn't be true with PDPs since they can output at 96Hz but accept a 30/60Hz signal which isn't evenly divisible.

If this isn't true and a 96Hz PDP is fixed then wouldn't it require an additional type of telecine to display 30/60Hz signals to make it evenly divisible?

Someone please school me, thanks!

LarryInRI's Avatar LarryInRI 05:25 PM 05-04-2014
Movies traditionally are made at 24 frames per second and shown using double shutter at 48 fps. Double that and you get your 96 fps.

Larry
el pablo's Avatar el pablo 05:40 PM 05-04-2014
Quote:
Originally Posted by LarryInRI View Post

Movies traditionally are made at 24 frames per second and shown using double shutter at 48 fps. Double that and you get your 96 fps.

Larry

Thanks for your response Larry. I'm aware of that but am assuming a PDP that can output 96Hz isn't fixed at that refresh rate because it wouldn't be evenly divisible for 30 or 60hz input. This would lead me to believe that a PDP that can output 96Hz can also output 60Hz opposed to LCDs which have fixed refresh rate output which are evenly divisible. (i.e. 120Hz vs 96Hz)

Can anyone else please chime in? Thanks again!
LarryInRI's Avatar LarryInRI 05:47 PM 05-04-2014
Quote:
Originally Posted by el pablo View Post

Thanks for your response Larry. I'm aware of that but am assuming a PDP that can output 96Hz isn't fixed at that refresh rate because it wouldn't be evenly divisible for 30 or 60hz input. This would lead me to believe that a PDP that can output 96Hz can also output 60Hz opposed to LCDs which have fixed refresh rate output which are evenly divisible. (i.e. 120Hz vs 96Hz)

Can anyone else please chime in? Thanks again!


Yes, a plasma indeed can display at 60 or 96 Hz. BluRay disks store movies at 24 Hz. I'm not sure what is confusing you.

Larry
el pablo's Avatar el pablo 06:52 PM 05-04-2014
So I was correct that PDPs can output multiple refresh rates opposed to LCDs that are always fixed.

It seems that explaining my rational for coming to this conclusion only led to confusion based upon your first response. I was only doing so someone could explain how PDP refresh rates work if I was incorrect. Thanks for taking your time to answer my question!
whipit's Avatar whipit 06:55 PM 05-04-2014
The only way you can use the 96hz mode is when you feed the tv 24p. Feeding it 30 or 60hz will get you 60p output.
el pablo's Avatar el pablo 07:09 PM 05-04-2014
Thanks for your input.

That is what lead me to believe that PDPs can output at different refresh rates i.e. 60 and 96hz etc vs LCDs which only output at a rate of 60, 120, or 240hz all the time based on the model.
KOF's Avatar KOF 11:49 PM 05-04-2014
Consumer plasmas can output in 60hz and multiples of 24hz. For a typical upper model Panasonic plasma, it can thus output in 48hz, 72hz, and 96hz with various levels of flickering. However, those multiples of 24hz can only accept 24hz as input. 48hz,72hz, and 96hz can't be accepted natively. That's why judders are still present on those modes.

Now, a professional Panasonic plasma can behave closer to LCDs. It can even accept 120hz natively, something not possible with consumer plasmas without hacking.
el pablo's Avatar el pablo 12:12 AM 05-05-2014
Quote:
Originally Posted by KOF View Post

Consumer plasmas can output in 60hz and multiples of 24hz. For a typical upper model Panasonic plasma, it can thus output in 48hz, 72hz, and 96hz with various levels of flickering. However, those multiples of 24hz can only accept 24hz as input. 48hz,72hz, and 96hz can't be accepted natively. That's why judders are still present on those modes.

Now, a professional Panasonic plasma can behave closer to LCDs. It can even accept 120hz natively, something not possible with consumer plasmas without hacking.

Wow, I didn't think an output of anything over 96hz was possible on a PDP!Thanks for the info!

How does plasma technology allow for the output of different refresh rates while LCD technology does not? Thanks again!
KOF's Avatar KOF 01:02 AM 05-05-2014
Quote:
Originally Posted by el pablo View Post

Wow, I didn't think an output of anything over 96hz was possible on a PDP!Thanks for the info!

How does plasma technology allow for the output of different refresh rates while LCD technology does not? Thanks again!

48hz and 72hz isn't too useful because of flickers, but at least it's there.

So here's how it goes. My Panasonic plasma for example can output in either 60hz or 48hz. When running at 60hz, it can accept 24hz, 30hz, and 60hz. When running at 48hz, it can only accept 24hz. BTW, movies aren't the only ones plasmas can accept at 24hz. My Geforce for example can output 24hz natively so it's possible to display games at 48hz. It's not terribly useful because of flickers, but there you go.

I'd love to play games on one of those professional Panasonic plasmas someday. It will natively support both 60hz and 120hz, just like CRTs, yum.
whipit's Avatar whipit 05:24 AM 05-05-2014
If the tv has a d-sub connector it can accept higher rates at reduced resolutions. The official max in the list for my G10 is 85hz @ 1024x768. It also states that the refresh can go from 48 to 120hz and the resolution max is 1280x1024. So it looks like there's some options with that kind of input. In the same list HDMI and Component had shown standard resolutions/rates.
el pablo's Avatar el pablo 05:08 PM 05-06-2014
Quote:
Originally Posted by KOF View Post

48hz and 72hz isn't too useful because of flickers, but at least it's there.

So here's how it goes. My Panasonic plasma for example can output in either 60hz or 48hz. When running at 60hz, it can accept 24hz, 30hz, and 60hz. When running at 48hz, it can only accept 24hz. BTW, movies aren't the only ones plasmas can accept at 24hz. My Geforce for example can output 24hz natively so it's possible to display games at 48hz. It's not terribly useful because of flickers, but there you go.

I'd love to play games on one of those professional Panasonic plasmas someday. It will natively support both 60hz and 120hz, just like CRTs, yum.

Quote:
Originally Posted by whipit View Post

If the tv has a d-sub connector it can accept higher rates at reduced resolutions. The official max in the list for my G10 is 85hz @ 1024x768. It also states that the refresh can go from 48 to 120hz and the resolution max is 1280x1024. So it looks like there's some options with that kind of input. In the same list HDMI and Component had shown standard resolutions/rates.

As far as I can see there are only a few PDPs confirmed to input/output 120hz and they are all Panasonic models:

http://www.avsforum.com/t/1438092/list-of-hdtvs-with-120hz-native-refresh-ability-forcing-1080p-120hz-via-dvi-or-hdmi-from-computer

It seems this is possible because the way these panels display 3D Bluray at 60fps (120hz). With other input I don't believe they output 120hz without connecting a compatible 120hz PC GPU:

http://www.blurbusters.com/overclock/120hz-pc-to-tv/

It would be interesting to see Bluray output from one of the compatible GPUs to see if it appears any different than 96Hz. There may be no difference between 24p 96hz and 120hz (difference between repeating the frame one more time) and the only benefit with 120fps PC games.

I shouldn't have explained my rational for believing why PDPs can output variable refresh rates. I should have just asked the question if they can (the post subject title) because I led people to believe I was asking something different. If PDPs did have a fixed refresh rate (i.e. PDPs that can output 96hz were fixed at 96hz) I was trying to understand how they could output 30 or 60hz because not evenly divisible. If these panel did have a fixed 96Hz rate then the only way I thought 30/60hz input could be displayed is some special type of telecine to convert to 96Hz.

Of course I was way over thinking everything and should of already known the answer (they do both so 30/60hz input output at 60hz and 24hz at 96Hz which is what made sense) Because I knew LCDs use a fixed refresh rate I was questioning myself and thinking maybe PDPs were the same because why could one and not the other? (Which I'm still trying to figure out) Of course not having variable refresh rates on a 120Hz LCD isn't an issue because 24, 30, and 60Hz are all evenly divisible. Then there are those that don't care about 24P to begin with.
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