Do PAL tv's offer better Picture Quality than NTSC?

[antisense]

I have been wondering lately whether or not PAL tvs give a better overall picture than NTSC tubes because they (PAL) dvd specs are
MPEG-2, 625/50 (PAL): 720x576
while NTSC. is 720x480. It seems that on this face value (and the fact that PAL DVD's have to use more MB for the movie than NTSC dvds, that we (North American's and the Japanese and whoever else uses this-I think they use it in Japan, maybe they don't) are getting hosed. Anyway, I was just curious if any one out there had seen a dvd on a PAL tv and a NTSC tv and had any comments. Or if anyone would like to help me out-regardless if they have seen a PAL tv or not, please do so!
:P

[resnullius]

pal does have a better image but it's not very visible....

[antisense]

What do you mean that the "image is not very visible"?? That is quite an odd thing to happen- a tv that you can't see the picture very well, you might as well make a radio with awful speakers! Please could you explain a little more, thanks.

[kinneera]

If you do the math, the odds are that you're actually going to get worse quality with PAL. Since the physical medium is the same, the limiting factor is going to be storage space. If you have to fit the same length movie into the same amount of space, but the PAL resolution is higher, then you will have to encode more pixels with the same number of bits. Thus, you would actually lose quality. This is similar to the discussions of why 720x480/576 is almost never a good resolution for the low bitrates of XVCD and SVCD.

That said, most dual-layer DVDs have some space to spare. If the PAL disc leaves a little less unused space, then in theory, the extra lines of resolution are going to make it look slightly better. But as resnullius said, for the purposes of the human eye viewing it on an analog TV, the difference is going to be minimal.

[Robbins1940]

This may be slighty off topic but i have seen Fox News and CNN over here in the UK. And the picture quality is terrible.

I mean I get better quality from a £500 camcorder and thats saying something.

Is all American TV got this very bad quality or is it just the news channels that can't be borthered to use better cameras?

David

[Ashtrader2000]

There's no real visible difference in quality. I have watched both and cannot tell them apart on resolution (or compression for DVDs). The more important difference is, that with NTSC, it's possible to regulate the colors from TV to TV. In practise, this means, that two NTSC TVs don't show the same colors. True videofreaks therefor call NTSC: Never The Same Color!

About that little calculation saying, that PAL should be more compressed; Don't forget, that PAL only has 25 frames per sec., whereas NTSC has approx. 30.

Now to the guy who has seen CNN i UK: CNN in UK on a PAL TV is shown in PAL format. Can't use that for comparison. The poor quality must have something to do with your connection to the sattelite/whatever, because I see CNN (and other American channels) fine on my PAL-only TV (in Denmark)!


Ashtrader

[t0nito]

I used to live in canada (NTSC) and now I'm in portugal (PAL), so I've been able to watch both systems. I also see CNN via satellite here and the quality issue is not because NTSC is bad it's because there has to be a format conversion of the systems, since NTSC has 96 lines less and 10 fields (5 frames) more than PAL the image has to streched like If you were resampling a a foto to a bigger resolution so it get blurry that's why NTSC looks crappy when converted to PAL but It's clear when viewing in the original format. PAL has the advantage of having a higher resolution, it displays a clearer images than NTSC 'cause there is more lines where the image can be displayed. So this is the thing:

Source: TV:
NTSC -> NTSC Good quality picture
PAL -> PAL Better quality pictures (Higher resolution)
NTSC converted-> PAL Blurry Image (resolution resampling) jerky on faster movements (field conversion 60->50)
PAL converted -> NTSC blurry but better than NTSC ->PAL, Jerky on faster movements (field conversion 50->60)

Get it?

[xepa w0011]

I've noticed that the frame rate has mostly been ignored for this discussion. If you do the math taking the frame rate into account, you can see there is a very good reason there is little visible difference between the two formats. If we look at the amount of information contained in 1 second of uncompressed video we get:

ntsc: (720x480pixels)x(30f/s)=10368000 pixels/sec.
pal: (720x576pixels)x(25f/s)=10368000 pixels/sec.

If we are talking about DVD where we have plenty of space to work with, the results should be virtually indistinguishable (assuming all other factors are equal). The visual differences would be a matter of preference (i.e. does more resolution look better, or more frames per second?).
Either way, the same amount of information/second is transmitted in the stream.

If we are talking about (s)vcd, perhaps on CD-R(W), then it's possible that in addition to the personal preference the efficiency of the compression makes a difference too. I'll leave the math to the video gurus that have an intimate knowledge of the mpeg compression algorithm. I suspect the difference is either non-existent or too small to make any difference there too. I know mpeg compression relies heavily on storing only the changes between frames when possible. On one hand, for the same video segment there would be an equal number of scene transitions (per sec, we'll say), so at 30f/s, we would be saving more frames. On the other hand, with pal, each frame we save would contain more information, so its a toss-up again.

Maybe I'll test this out and see which one compresses better in the real world (if I can figure out a way to do this without introducing other variables).

This is a great site and forum, btw, and has helped me out in capturing and burning video.

(Btw, I rounded the frame rates above for convenience. The actual frame rate for ntsc is 29.97f/s. You'll have to decide if the .03 f/s is a significant difference.)

[3dcandy]

I've been watching PAL for like ever, and when I've watched NTSC it just seems a little "washed out" in direct comparisons..... mind you, that was while on holiday, and I suppose it just what you're used to. The biggest difference for me seems to be the colours.....

[kinneera]

To the people doing framerate comparisons, remember that most - not all, but most - NTSC DVDs are actually going to be encoded at the film framerate of 23.976 and then telecined on the fly. Again, more bits for NTSC, although the benefit is likely going to be negligible.

[Mirror_Image]

This may be slighty off topic but i have seen Fox News and CNN over here in the UK. And the picture quality is terrible.

I mean I get better quality from a £500 camcorder and thats saying something.

Is all American TV got this very bad quality or is it just the news channels that can't be borthered to use better cameras?

David

This is a shining example of a:

False Dilemma

Definition:

A limited number of options (usually two) is given, while in reality there are more options. A false dilemma is an illegitimate use of the "or" operator.

Putting issues or opinions into "black or white" terms is a common instance of this fallacy.