Question about 24p

HellsChicken

Hello,

I've been considering getting the Panasonic TH-42PZ800U, but I've read that while it does support 24p, it really flickers and is hard to watch. That's the only thing really holding me back from buying one of these.

So my question is, how important is 24p really? Will that mean that HD content (say, from Blu-ray) will look bad if you don't have it enabled? Or is it easily livable without it?

Thanks!

Loves2Watch

It is certainly livable without it as most TV owners who don't have it will tell you. It certainly doesn't bother me not having it on some of my TV's and there are only a few, far and between instances where it COULD be of benefit.

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rbinck

Specific details on that set do not seem to be available as to how they handle the 24p input. I'd be suprised if it would flicker though.

What would be important for a set that accepts a 24p input signal would be to display it at a multiple of 24p. That usually means 72 Hz for most plasma TVs. That make the picture flicker and judder free. If the set converts the 24p to 60 Hz for display, it won't flicker, but the judder will be there.

The only benifit would be if you hook up a Blu-ray player that will output 24p. Regular TV watching there is no benifit.

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HellsChicken

Hey guys, thanks for the responses.

The part about flicker was from cnet's review: (unfortunately i can't link to the review because i haven't made 5 or more posts, but it's fo the 50" model of the same set, the TH-50PZ800U)
In particular, the following paragraph:

What is normally the appropriate/"necessary" times to be using 24p anyway?

BuTal63

It's early in the game, but the Cnet review nearly exactly mirrors initial owner experience with the new 800 series, as evidenced by many flicker complaints when attempting to use 24p, some also saying it's actually "unwatchable." General feeling thus far is that 48hz is inadequate to prevent the problem and that Panasonic should have gone to at least 72hz as Pioneer Kuros do.

It's being suggested that Panny should modify further production and somehow retrofit units already produced. I wouldn't hold my breath waiting for that.

On the other hand, nearly everyone seems very pleased with 60hz performance so far.

rbinck

If they are using 48 Hz update that explains the flicker.

As far as what is appropriate times to be using 24p anyway, it would be just as what they described. When you hook up a Blu-ray player set to 24p output. But if that causes flicker, the there is no time when 24p would be appropriate, imo.

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mobiushky

Since no one seems to be giving the foundation details, it might help to really understand what "24" is and why it is even a discussion.

To start with, you have to know that all movies are filmed at 24 frames per second. (the numbers are actually 24 * 1000/1001, but let's keep this simple...) When they show a movie in the theater, flashing 24 frames per second will result in an incredible flicker on the screen. So they use essentially a shutter that flashes at 3 times the rate of the film, ie 72 times per second. That get's rid of any flicker. The problem comes when you try to transfer that movie over to TV media. For the longest time, with DVD, the film was transfered using 3:2 pull down onto the DVD.

3:2 (or 2:3 which ever you prefer) is a process of unequally displaying frames to arrive at an even 60 frames per second. The process shows the first frame 3 times, the second twice, then 3, then 2, etc... like this:

AAA-BB-CCC-DD-EEE-FF-GGG.....

When you add them all up, you get 60 frames instead of 24. However, as is the case with any kind of forced processing, some unnatural results can occur. The term "judder" was used to explain the results of the 3:2 pull down. Since PQ is subjective, some people complain more about judder than others. Cnet defines judder as:

So, what if you could replicate the same FPS as a movie? what if you could avoid 3:2 pull down altogether? Enter, BD and 24p. The problem is, not many TV's are really capable of true 24p rendition. Some say they can, but in truth, they just do a 3:2 pull down internally which ends up with the same result as before.

Pioneer is a good example, though not the only TV that does it right. Pioneer, instead of forcing 3:2 pull down, actually changes the refresh rate of the TV from 60Hz (standard for most TV's) to 72Hz. The result is 3:3 (or the same as a movie theater). Judder is gone and all the other issues with 3:2 pull down.

So what about 120Hz tv's? if you did the math, you noticed that 120 is a multiple of both 60 (X 2) and 24 (X 5). Result, no 3:2 pull down.

So where is it appropriate? Any time you watch a movie on BD as they are all mastered at 1080p/24Hz. Will you notice it? If you don't have a problem with DVD's, you might not since you've been watching 3:2 all along. But, if you see it (I do) then you will care.

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Main Setup:
Pioneer PDP-5070HD
Pioneer VSX-80TXV
Dish Vip622
PS3 (120Gb), someone tried to tell me my BD player could play games too, what an idiot.
Logitech Harmony 1000 remote
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BuTal63

Very nice mobiushky! Thanks.

HellsChicken

Thanks for the awesome reply, Mobiushky!

mobiushky

A good example of how 24Hz works to me was The Italian Job. I just watched in on BD last night. The PQ is not great btw, but that's a different issue. What struck me was how smooth the pans were. And there are a lot of them in that movie. The funny thing was, I wasn't even looking for it. About 1/3 of the way into it, I started thinking man that looks great, but the PQ wasn't. So what is making this so different to me? I finally figured out that anytime there was a pan across something, it was crystal clear. There were a few that were not the best, but not enough to really matter. Those are the times that 24Hz really pays off.

__________________
DRM is roughly the equivalent of poking you in the eye, repeatedly.
----------------------------------------------------
Main Setup:
Pioneer PDP-5070HD
Pioneer VSX-80TXV
Dish Vip622
PS3 (120Gb), someone tried to tell me my BD player could play games too, what an idiot.
Logitech Harmony 1000 remote
All Klipsch speakers

Bedroom Setup:
Sony KDR-40XBR4
Dish Vip622
PS3 (80Gb, no BC) I think I have too many PS3s.
Sony Commander RM-AV3000

mbpautz762

I was always under the impression that anything shown in less than 60 Hz would appear to flicker, since the human eye can only detect individual frames (hence flickering) when flashed less than 50-60 times a second. That would definitely explain why the CNET reviewers had such a problem with flickering at only 48 hz, and also why those at 72hz would not have those problems. Does the panny TH-pz800U have a 72Hz setting for 24p, or is it only 48Hz?

First post, by the way

trekker

It's 48Hz.

mvftw

Who else except Pio does it at 3:3???