Or Questions...

IF a DV tape can only hold 720x480, Do Pal cameras compress both horizontally and vertically? Also if it's 576 lines of progressive horizontel resolution, would it then still be 960 and 720 lines of vertical resolution, or something different in order to get an accurate pixel count for 16:9 and 4:3 something like 1150 and 850 or is it still the same?

thanks
Nick

It's the same throughput whether it's NTSC or PAL. PAL is higher resolution, but at a slower frame rate. The data rate is the same either way.

Chris,

When you point it out like that, why aren't most of us using PAL cameras then in order to capture at higher resolution?

Obviously the lower frame rate is still 'acceptable'. And according to my Vegas5 manual, I can import PAL and export to NTSC if I'm willing to render.

Are there other big disadvantages to using a PAL camera stateside given that software can compensate for the PAL/NTSC system differences? Does rendering to NTSC negate the inherently better PAL resolution? Are the render times for this horendous?

Because American TV sets can't display PAL - they only display NTSC format. European sets are the opposite.

It has been, in fact, quite common for people shooting video with the intent to go to film to shoot on PAL camereas for some time, but if you're shooting for television it's much better to just shoot in the format it'll eventually be broadcast in.

Patrick

I think there are many people who wonder why the U.S. is still NTSC.

PAL cameras aren't as common over here because the millions of existing NTSC monitors aren't PAL compatible -- PAL's 50i frame rate flicker can be difficult to watch in a room lit by flourescents cycling at 60 times per second -- all of our legacy video is all NTSC -- it's more difficult to buy PAL gear in the U.S. -- there are quite a few reasons!

<<<-- Originally posted by Nick Hiltgen : Or Questions...

IF a DV tape can only hold 720x480, -->>>

DV Tape is merely a magnetic media, and it can hold practically anything you can write on it. NTSC DV data is 720x480, PAL DV data is 720x576, and DV tape is used in HDV formats so in HDV you can put 1280x720 and 1440x1080 on DV tape. So the tape is irrelevant to the discussion.

The "DV" video standard is what you're referring to, and in DV all formats run at 25 megabits per second. NTSC uses 720x480 at 30 "frames" per second, whereas PAL gets higher spatial resolution (720x576) at lower temporal resolution (25 "frames" per second). The different specs cancel each other out, and the net data rate stays at 25 megabits per second.

Here in Europe over the last 10 years or so it's increasingly common to find domestic TV receivers and VHS players to be able to process NTSC signals in addition to the PAL standard. I recently connected a friend's NTSC camcorder to my Hitachi PAL TV and it was able to display video and audio, albeit in a "pseudo PAL" mode. Same with my VHS player (yes - I still have a VHS due to the many hundreds of legacy tapes dating from the mid-70s!) - it will play back my NTSC dupes quite happily.

The question of why we're not all using PAL now is simple (as Chris implied) - namely that we're dealing with the matter of huge scale. North America is a big, big market.

Still, one day a new common standard will render PAL and NTSC (and SECAM) obsolete anyhow.

Colin

<<<-- Originally posted by Barry Green: The "DV" video standard is what you're referring to, and in DV all formats run at 25 megabits per second. NTSC uses 720x480 at 30 "frames" per second, whereas PAL gets higher spatial resolution (720x576) at lower temporal resolution (25 "frames" per second). The different specs cancel each other out, and the net data rate stays at 25 megabits per second. -->>>

Barry, thanks for writing very clearly something I already knew but didn't recall (it seems the more numbers, facts and figures I read, the fewer of them stick; grey matter available is inversely proportional to an increasing complex world).

Here is the gist of my question though: If the temporal resolution of 25 frames per second is considered adequate for entertainment viewing of video sources, why wouldn't I want to maximize the spatial resolution to increase image quality?

I'm very familiar with temporal resolution as I have worked on the development of combat flight simulators for my day job. They require sixty frames per second as an absolute minimum and for the size of some of the projection systems used, you can imagine the complexity of the computer database to provide resolution sufficient to make the pilot feel 'he's there'. But we don't require 60 at home (really even 60i is only 30 if you think about it), and 25 is 'good enough' in the rest of the world.

So...isn't using the available DV25 bandwidth for addtional resolution instead of squandering it on un-needed frame refresh a really good thing?

Hi Patrick,

I live in North America and for the last year have been using a Canon XL1s PAL version for making short films for a couple of reasons:

1) The vertical resolution is 20% higher, but this only mostly matters if you plan to do a 35mm film blow up.

2) The frame rate is 25fps (50i) which is much closer to the frame rate film is shot at (24fps). This is great for 2 reasons: again easy to convert over to 24fps film, and secondly adds somewhat of a "film look" look when converted to NTSC. Note: There are many methods, but one involves converting PAL frames to progressive frames and then performing somewhat of a 3:2 pulldown to fit 30fps / NTSC.

3) 50i PAL shot can be converted to 24p with greater accuracy then trying to go from 60i to 24p.

Before the DVX100 this is what I was doing to make films and still use today, needless to say I will be upgrading to the XL2 as soon as it comes out and my Canon XL1s PAL is for sale should anyone be interested - please just check the classifieds section of this site. The camera is mint and only has 6 hours use on it.

If anyone has any questions about shooting PAL for NTSC I can answer them. I also have huge stills on my website if anyone wants to have a peek - click the image to start the slide show.

Oh yeah, as for rendering times to convert PAL to NTSC it takes me 4 minutes for every 1 minute of video I need to convert on a 2.2GHz Intel Laptop. The results would probably be faster on a desktop.

Dennis,

Are you going to purchase the NTSC or PAL version of the XL2?

Yes I forgot to indicate which way I would be going this time.

Despite the fact I've mastered converting PAL to NTSC and impressed people at film festivals with the results of my conversions and work... I'm putting a little more value in how much time I spend in post and am opting for a camera that will just shoot 24p in camera so I can do more quicker.

It's funny because for years both Sony and Canon were telling people who wanted to make DV films on their prosumer cameras to just shoot on PAL if their need was 24fps. Then BANG out came the DVX100 and they both missed out on that market. Canon is a little late now with their 24p camera and I doubt that Sony will even release one. Sony's going straight to prosumer HD later this year and I will bet my new XL2 that it will not offer 24p.

Barry thanks for the clarification, you're absolutely right, I think I just got ahead of myself in asking the question. I meant DV format... maybe... I think...

SO the resolution for a PAL XL2 will be 576x720 and 576x960? Are PAL pixels just compressed horizontally? Or is it simply that PAL pixels are 1x.93 or something along those lines?

Thanks to everyone for their replies, I owned a pal xl1 but I never worried about resolution until now because of progressive scan.

Nick

The resolution for a PAL XL2 will be 720x576. There is no 960x576, all PAL DV is 720x576 regardless.

All DV pixels are non-square. NTSC pixels are taller than they are wide, which is why you can pack 720 of them on a line where theoretically only 640 of them should fit (think about it: 640x480 is a 4:3 ratio, 720x480 is not... 720x480 is actually a 3:2 ratio). NTSC widescreen pixels are wider than they are tall (at about a 1.2:1 ratio). PAL pixels are normally a little wider than they are tall (because a PAL TV set is still 4:3, but 720x576 is not a 4:3 ratio). PAL widescreen pixels are even wider.

Computer pixels are square. Video pixels never are... until you get to HDTV. In HDTV the pixels are square, 1920 x 1080 is a 16:9 ratio, and 1280 x 720 is also 16:9.

Despite the fact I've mastered converting PAL to NTSC and impressed people at film festivals with the results of my conversions and work...

Dennis,
If you've mastered the PAL to NTSC thing, I'd urge you to reconsider the PAL XL2 over the NTSC version. You get better resolution with the PAL version, and you don't have to deal with any 3:2:2:3 pulldown nonsense in editing. You're the perfect type of user who would benefit from the PAL version because you've already been dealing with it in an NTSC environment.
Needless to say, I'm a die-hard PAL advocate:
http://www.colddayinhellthemovie.com/VC25P.htm

Barry

I understand you I think, but does that mean that there will be no 16:9 option on the xl2, I'm guessing no, so does that mean that the camera will then compress the information onto the PAL DV tape? Are you saying that there is no 960x576, like there is no 960x480 (because on tape it is compressed to 720x480) or do you mean that the vertical resolution suffers on widescreen pal because it's still 720x576 only now the 720 must cover a larger space so the image quality suffers. Could this be? Could PAL have something that is worse then NTSC? Someone help my world is falling apart!

The PAL XL2 is most definitely 16:9. It just takes the 960x576 patch off the CCD and scales it to become a 720x576 PAL frame.

Whew, that was close.

SO if you were to pull an image straight off the chips in 16:9 mode then you would have an image that is 960x576 (or close to it) and then once it's recorded to tape it goes through some sort of algorhythim that compresses if to 720x576, I might have missed it but barry what's your take on SMPTE time code on the XL2 I've heard that their simply isn't room to record smpte time code on to a minidv tape (that's why you have to use dvcam or somethign along those lines) or do you haveto use dvcam to get smpte on the xl2?

Thanks again for all of your help

Nick,

4:3 PAL is 720x576 and goes to miniDV tape at 720x576 25fps
4:3 NTSC is 720x480 and goes to miniDV tape at 720x480 30fps

The Canon XL2 records 16:9 as follows:

16:9 PAL is captured on the CCD using 962x576 and goes to miniDV tape at 720x576.

16:9 NTSC is captured on the CCD with 962x480 and goes to miniDV tape at 720x480.

The XL2 PAL has 800,000 effective pixels
In 4:3 mode you get 410,000 pixels
In 16:9 mode you get 550,000 pixels

The XL2 NTSC has 680,000 effective pixels
In 4:3 mode you get 350,000 pixels
In 16:9 mode you get 460,000 pixels

I agree it is somewhat misleading because everyone is debating whether or not the extra pixels (962 horizontally) are benifiting the overall image despite the fact they are only being "saved" or "captured" to tape as 720 pixels horizontally. Technically YES it is beneficial - but will we see the difference? I believe the critical eye will because films shot on 35mm film put on DVD at 720x480 appear to have much more detail than shooting 720x480 on your camcorder and burning to DVD.

<<<-- Originally posted by Dan Vance : Needless to say, I'm a die-hard PAL advocate: http://www.colddayinhellthemovie.com/VC25P.htm -->>>

Holy shit Dan, I just visited your site and saw your home built "one-of-a-kind" film-look digital camcorder using 3 x 1/2" CCD PAL camera with 700 lines of resolution! That is wicked!

How does one go about acquiring one of those and for how much?!?

In your trailer did you adjust your frame rate from 25fps to 24fps and then perform a 3:2 pulldown to 30fps in After Effects? Or is the trailer still in 25fps?

Great work man!

I can't believe this guy built his own camera...

Thanks! Yeah, it was quite the project, but I'm really happy with the results. The clip is just 25P. I'm working on a "real" trailer which will give more of a feel for what the movie is about, but I wanted to post something that would allow people to at least see the "pseudo progressive scan" effect.
I don't know if I recommend building one though. Except for the small CCDs, that XL2 is looking really good. Although I'm really spoiled now by going direct to disk. Even if I got an XL2, I'd bolt a CAPDIV hard drive to it and skip the tape.

Dan, I have an electonics background as well so I could completely appreciate your "quest" and what you were trying to achieve with your design in the VanceCam25P.

I was showing a filmmaking buddy of mine your trailer (we spend more time talking about how to get the highest quality images possible out of consumer grade equipment than actually making films - LOL) and we loved the way the footage looked. It wasn't just the progressive image that was cool, it was just the detail in all areas of the frame and even the color was unlike anything I've ever seen coming out of a consumer video camera. I've owned the VX1000, VX2000, XL1s and the footage from your cam in my opinion is so raw and natural it is mind blowing.

Do you think the quality you're achieving is done more so because of the 1/2" 3CCD - or because you are not using the miniDV format and going straight to a hard disk recorder? In other words, have you tried recording your analog signal directly to miniDV through a PAL camera with analog inputs? I'm trying to discover whether it is the miniDV format or the CCD that holds back quality from being all it "could" be.

Any insight would be appreciated.

P.S. Do you really think the XL2 will be comparable to the VanceCam?

Let's stay on topic -- please don't hijack the thread!

I met Dan Vance at NAB this year and he is an amazing fellow with an amazing homebuilt camcorder (the Vance Cam). But please take any Vance Cam discussion over to our Alternative Imaging Methods forum -- thanks!

By the way, the PAL XL2 CCD target areas are as follows:

16:9 target area is 960 x 576 (appx. 550,000 pixels)
4:3 target area is 720 x 576 (appx. 410,000 pixels)

Hope this helps,

(Dennis, I'll email you directly about your questions so that this thread stays OT.)
The XL2 has a higher pixel count than some 1/2" CCDs, even more so in 16:9 mode, because you'd have to crop a 1/2" 4:3 image and lose about 20% of your pixels anyhow. So in comparing the XL2 to a 1/2" PS camera, you have to weigh the advantage of more pixels against the disadvantage of smaller CCDs, and the other features/limitations of each camera.

I don't wish to grind this camera pixel count Vs DV pixel count topic into the ground but I think one aspect that is confusing some, including myself, is that even though DV is 720X480 and the camera chip is (i.e) 962X480 the larger pixel count for the camera is still relevant to final quality. The difference between chip and DV frame size is often expressed in such a way that it simply sounds that the extra pixels are moot and therefor discarded, cropped etc. I know that this is not what our erudite posters intend, but that's how it reads to a layperson. i.e "It doesnt matter what size your chip pixel ratio is, it can still only adhere to the standard 720X480 DV frame" But if it were as simple as that then every camera chip need be no more than the pal or NTSC frame size.
One of you scholars should explain the advantage of a larger pixel count, even if it is (SOMEHOW) restrained to DV - i.e the DSR 500 16:9 or in this case the XL2! If it were as simple as previously stated then every camera chip need be no more than the pal or NTSC frame size.

Bill, there can be a difference that comes from having a CCD with more pixels than you can save to tape, but it does become a question of whether you can tell or not, and here's why:

The extra pixels are not merely discarded or thrown away. Instead, the image is downsampled. How this is done determines what the final quality of the image will be. Actually, merely discarding the extra pixels is one of the ways to accomplish this, but that's kind of the poor man's version - and it would have slightly worse quality than having exactly the same pixel count on your CCD and your final image. Why?

I'm going to draw a number square here for discussion:

1 2 3
2 3 1
1 3 2

(I just picked these numbers randomly). Now, say this is the actual image, but your CCD only has a 2x2 pixel count (4 pixels). In that case, if you focused the entire image on it, the pixel in the top left would record light from all of the top left "1", part of the top center "2", part of the middle left "2" and the upper left corner of the middle "3". The other three pixels on your camera would record similar patterns from their corners, so you would still have some portion of the information from the lost pixels show up in your image.

Now, if you had a 3x3 CCD that was capturing it but storing it as a 2x2 image, you'd have a different story. If it discarded the extra pixels, it would only store the four corner pixels and you'd lose all information about the pixels in between. So what you'd actually get is a worse picture than you would from just a 2x2 CCD. So nobody actually does it that way.

Instead, they'll use a weighted average system to compute values for the 2x2 image using the nearest neighbor pixels around it. There are varying methods of doing this. Whether or not this yields a better picture than just using a 2x2 CCD would depends on the quality of the averaging algorithm and the quality of the CCDs in question.

I'm not an expert on the algorithms, but I would expect Canon to be using one of the better ones. And there's no doubt that the new high-res CCD is better in all ways than the old low-res one from the XL1s. So theoretically, the image should be better for having a higher pixel count. But the question is how much better? If you compared the exact same pixel in an image taken from one camera with the exact same pixel from an image taken with the other, the difference would be very small. So when you look at the whole picture, it will be difficult to notice the improvement. But a good eye should be able to spot it.

I hope this helps and wasn't just all garbled.

In addition to Bill's point - just ask yourself why the stuff you watch on DVD (which is a 720x480 format) KILLS miniDV in resolution when you see it?

Hint : because the stuff you watch on DVD at 720x480 was not shot at 720x480 using prosumer 3CCD cameras.... it is usually shot on film and conformed to fit 720x480.

It's like this, shoot with high definition and burn to DVD (which again is 720x480) then shoot with a 720x480 camera and burn to DVD and watch. Why does the footage that originated on HD look crisper, sharper and better. This is the point I think many people here are trying to make.

...well from what Russell just said I am agreeing to disagree with myself.

It is true that for the most effective oversampling of a pixel it should happen at least 2.5 times - so recording at merely 1.5 times or even 2 times the resolution of the miniDV format may not in fact be benefical. In the case of the XL2 were not even talking whole numbers... we're talking fractions and that's the point I guess Russell has made. Well taken.

Yes, Dennis - you would get much better results from higher oversampling, and far superior if it were in whole number multiples (or at least "even fraction" multiples such as 1.5) of the target resolution. But theoretically the perceived resolution on an XL2 should be higher in part to its higher pixel count.

However, the real point is that having more pixels on your CCDs than on your final image (as the XL2 does) is far better than having less pixels on your CCDs than on your final image (as the XL1 and XL1s do), so there should definitely be a noticeable picture quality increase when upgrading from the older cameras to the newer one. And this is why Canon really isn't shortchanging widescreen or standard filmers, because both modes on the XL2 have at least as much resolution as the DV format. From a technical standpoint it's a good solution, although from an artistic standpoint a larger CCD target area (and hence better DOF) might have been nice.

And honestly - given the small oversampling in the 16:9 mode, I think it's going to be a very small number of people who can actually tell the difference.

Thanks to all for clearing that up.

<<<-- Originally posted by Bill Anderson : But if it were as simple as that then every camera chip need be no more than the pal or NTSC frame size. -->>>
It is as simple as that. For optimal video quality, that is what you want. You want the biggest pixels you can get, as long as there are enough of them to cover the frame. That's why in broadcast cameras you'll always see CCD's with just enough pixels to cover the frame.

<<<-- Originally posted by Russell Newquist :
However, the real point is that having more pixels on your CCDs than on your final image (as the XL2 does) is far better than having less pixels on your CCDs than on your final image (as the XL1 and XL1s do), so there should definitely be a noticeable picture quality increase when upgrading from the older cameras to the newer one. -->>>
True to a point. The # of pixels reflects the density of the pixels on the chip, and to some degree that reflects the resolution the camera is capable of. But there are other factors that are affected by the pixel count as well, namely latitude and low light performance. Tiny pixels have lousy light-gathering capability and can't hold as much of a charge so you get worse low-light performance. Resolution is not the sole determining factor for whether a video image looks good.

The optimal solution is to have just enough pixels to cover your frame size, and to have as large a chip as possible.

However Barry it would not be a benifit for Canon to reduce the pixel count. Would it? And according to your statement about having enough pixels to just cover the chip might read to a straight logic layman type like myself as meaning all chips have just enough pixels to cover them, otherwise they would simply not be covered (with those particular size pixels) Now it seems that there is an optimum size of pixel. What is its size? I don't understand how it could be just enough to cover the chip because you could do that with 4 or 6, but this would not be optimum. I'm going to assume that Canon optimised the pixel count for that size of chip otherwise I'll be wearing a straight-jacket before the XL2 hits the streets. Thanks for the info, it did help.

I meant "enough pixels to cover the format's frame". i.e., for DV in an NTSC camera, you want at least 720 x 480 pixels. For a high-def 1080 camera, you'd want to have at least 1920 x 1080 pixels. Any more than that would mean that the pixels were smaller than necessary, any fewer than that would mean limited resolution.

Canon put in enough pixels to cover the DV frame at a 1:1 ratio, considering that the CCD pixels are square and the DV frame pixels are non-square. However, had they made the chip be actually 16:9-shaped, those pixels could have been much larger, which would mean better light-gathering capability and less issues with latitude and noise. Because they only use a smaller 16:9-shaped chunk off a 4:3 CCD, they had to cram a lot more smaller pixels onto the chip in order to have enough to cover the DV frame with enough pixels to provide adequate resolution.

Just to indicate it again, shooting in true/native 16:9 on DV will
increase your VERTICAL resolution, NOT horizontal. Yes, horizontal
will have a higher sampling rate and this wider field of view, but
as indicated only 720 pixels of those are stored.

So beside the wider FOV and higher sampling the real benefit is
in the vertical resolution.

>>The question of why we're not all using PAL now is simple (as Chris implied) - namely that we're dealing with the matter of huge scale. North America is a big, big market<<

Colin, heres some trivia for you...

When I was stationed in West Germany in the late 70s, I brought my B&W NTSC TV with me and a step down voltage converter (from 220 to 110) but still at 50hz. I was able to pick up the local German TV station (video only) just fine. Great picture and everything.
Armed Forces Radio and Television Stations managed to broadcast 50hz with NTSC style interleaved audio so we had sound.

So... in order to save money...do the latest TVs have the built in ability to show either PAL or NTSC? And is the NTSC market simply not being told about it? hmmmmmm That would go with the North America gets dumbed down products theory, hehehehe