Plasma flickers when used as a monitor

[joe7dust]

I just bought a Panasonic TC-P42U2 42" 1080p. It says 600Hz but when I plug it in via HDMI it defaults to 60Hz. Looking at my video card settings I see that its actually only 24Hz when in 1080p mode but 60Hz in 1080i.

Needless to say 1080p flickers horribly at 24Hz and the 1080i 60Hz has some slight flickering as well. I bought this mainly because plasma is supposed to have superior fast-motion rendering without blur/flickering.... so this is a disappointment. Is there anything I do to increase the refresh rate and/or reduce flickering?

I also have a 120 Hz LCD and it does not flicker at all...

[Vianty]

The 600 Hz is misleading you. As a rule it means the refresh rate of the plasma (or LCD) display. The 600 frames-per-sec signal comes out from the frame rate converter. So 600 Hz is a result of upconverting of a video signal.

[joe7dust]

So what can I do to resolve this flicker? It isn't too bad in games, but when there is a lot of WHITE like this webpage it is awful...

[Vianty]

You should have started you purchase from looking at the input specification.
If the best input is HDMI 1080p 60 Hz try to use it with suitable video card. If you are not satisfied with the result, this TV is not for you.
HDMI version 1.4 can easily support 1080p 120 Hz. New 3D TV sets are equipped with such an input.
Check also the models with PC (VGA) input, maybe you can find something less expensive.

[Vianty]

Well, the HDMI 1.4 may still not support signal from PC at such a high rate as 120 Hz. Maybe 60 fps is the best you find amongst TV-s. This is because they are not built to be good PC monitors.

[edDV]

I just bought a Panasonic TC-P42U2 42" 1080p. It says 600Hz but when I plug it in via HDMI it defaults to 60Hz. Looking at my video card settings I see that its actually only 24Hz when in 1080p mode but 60Hz in 1080i.

Needless to say 1080p flickers horribly at 24Hz and the 1080i 60Hz has some slight flickering as well. I bought this mainly because plasma is supposed to have superior fast-motion rendering without blur/flickering.... so this is a disappointment. Is there anything I do to increase the refresh rate and/or reduce flickering?

I also have a 120 Hz LCD and it does not flicker at all...

24p (23.976p) film mode is intended for Blu-Ray players only or maybe your display card is emulationg a Blu-Ray player. In any case, you can't run a desktop at 24p. 1080i/29.97 (59.94 fields per second) will flicker for office type desktops with broad white areas. ATI and NVidia have flicker filters to reduce field flicker but these cause motion blur for video. Use these filters only if you need to work on documents at 480i/1080i. The TV may also have a flicker filter in the menus.

If the TV supports 1080p at 59.94 over HDMI try that. It will probably overscan. It may have a no-overscan setting (aka just scan). If not, you need to zoom the desktop on the video card. This scaling reduces quality.

That leaves VGA which is always progressive and usually has no overscan since it is intended for computers or game devices. If supported, try 1920x1080p/60 in VGA. All other sizes will be scaled to 1920x1080p by the TV but the scaling will reduce quality.

As said, 600Hz is an internal resample in the TV. Input support is usually limited to 23.976, 29.97 or 59.94 fps.

23.976 x 25 = 599.4 Hz
29.970 x 20 = 599.4 Hz
59.940 x 10 = 599.4 Hz

[Vianty]

If you watch TV program, do you see flicker? Also looking out of the corner of your eye?
The frame rate converter should function all the time no matter of the input. PDP refresh rate 600 Hz should be sufficient for making viewing experience flicker free.
If the TV program looks flicker free, than maybe there's something wrong with signal processing from HDMI. You should find out how the identical models behave, if it is a feature or anomaly.
Better ask for authorized Panasonic service advice in this.

[joe7dust]

@Vianty
Yes the flicker is much more noticeable out of the corner of my eye, why do you ask? Right now I'm using only a 9600 GT with DVI-I out and a DVI-I to HDMI conversion cable so that could be contributing. I just ordered a HD 5870 with native HDMI out and HD audio built in so maybe that will help in a few days.

[edDV]

@Vianty
Yes the flicker is much more noticeable out of the corner of my eye, why do you ask? Right now I'm using only a 9600 GT with DVI-I out and a DVI-I to HDMI conversion cable so that could be contributing. I just ordered a HD 5870 with native HDMI out and HD audio built in so maybe that will help in a few days.

Did you set the 9600 GT to 1920x1080p @59.94 fps? Did the TV take it? If the TV won't accept 1080p/59.94, try the VGA port.

[joe7dust]

I can only do 1080p at 24Hz, the best 60Hz is 1080i.

I don't think I have a VGA port it has 3 HDMI...

[edDV]

I can only do 1080p at 24Hz, the best 60Hz is 1080i.

I don't think I have a VGA port it has 3 HDMI...

Then this plasma HDTV was not intended for PC connection.

24p is for stand alone Blu-Ray players only.

Did you ID the make/model? I'll re-read above.

[edDV]

Looking at this
http://www.amazon.com/Panasonic-TC-P42U2-42-Inch-1080p-Plasma/dp/B00392141U

Your TV only has HDMI and analog component inputs for HD. Not VGA for progressive non-overscan.

The manual should give more detail. Do you have a link to the manual?


PS: I'm unaware of a display card that outputs 24p (23.976) even from a Blu-Ray disc. Can anyone educate me?

[joe7dust]

Do you know what causes vertical smearing? Top to bottom motion looks very pixelated like at some moments in time what is supposed to be only 1 pixel wide is then 2 pixels wide. With CRTs/LCDs its the horizontal motion you gotta look out for because of "vertical tearing", yet that can be solved by V-Sync. I guess what I need now is H-Sync? lol..

[Vianty]

I didn't find how Panasonic define the refresh rate on their TV-s. The 600 Hz may be not true, I mean the display itself can be for instance only 240 Hz, maybe less.
Anyway, there is a chance you can switch this frame rate converter off. This is the function which tries to predict motion and produce more sharp image of moving objects. This algorithm is not perfect, it may cause the effect you are describing.
You may as well be more sensitive to picture flickering than average person.

[jagabo]

PS: I'm unaware of a display card that outputs 24p (23.976) even from a Blu-Ray disc. Can anyone educate me?

I was able to get 1920x1080p24 from my Nvidia 8600 GT (dual DVI). I think most cards can do this with the right driver.

[edDV]

PS: I'm unaware of a display card that outputs 24p (23.976) even from a Blu-Ray disc. Can anyone educate me?

I was able to get 1920x1080p24 from my Nvidia 8600 GT (dual DVI). I think most cards can do this with the right driver.

Right, I forgot.

None of my monitors or HDTV sets will accept 23.976p. I'd expect a 23.976 desktop to flicker.

[nikseldon]

I just bought a 50 plasma and have the same problem with the screen flickering due to the 60Hz. It flickers on all HDMIs and it flickers in its own menu and player.

The strange thing is that it does not seem to flicker while watching regular TV. I have even looked at images with a lot of white, even static images with white and it does not appear to be flickering at all.

Is it possible that the plasma TV does not flicker on DVB-C signal while it flickers on all other inputs?