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Canon XL and GL Series DV Camcorders
Canon XL2 / XL1S / XL1 and GL2 / XM2 / GL1 / XM1.

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Old February 24th, 2010, 03:10 PM   #16
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Originally Posted by Perrone Ford View Post
...HD on DVD should look VASTLY superior to SD...
That is certainly not true when both are compressed to fit around 1-hour of highest possible quality mpeg2 files on a DVD disc.

That is why I MUCH prefer to use an XL2 compared to an XL-H1 if the final material is only for DVD disc (and I produce and sell thousands of DVDs, so always try to produce highest possible quality).

In terms of original footage, of course the HD files are far better...but certainly not when HDV and SD Avi raw files are finally compressed on to a DVD disc.

If HD Blue-Ray is your final end product, then the HD cameras such as XL-H1s etc will produce a far higher quality compared to the SD. - (Although XL2 footage uprezzed to 720P can still look very good indeed).

Chris is also of course right in that all the SLR/DSLR lenses available to fit the SD XL2 via an adapter will also fit the HD XL-H1 line of cameras using the exact same adapter.
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Old February 24th, 2010, 03:28 PM   #17
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Thanks Tony, me too (apart from selling thousands of dvds). What I do not understand is how (all else being equal) downresd footage can look better than footage shot at the delivery resolution. I can readily understand why downresd footage would not look as good. If anyone has an objective rational explanation I would really like to hear it.
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Old February 24th, 2010, 04:25 PM   #18
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Originally Posted by Perrone Ford View Post
Colin,

When I say "didn't change" I mean only that if you had a television (in the US) that was purchased in say 1955 and it was still operational, you could plug it in in 2009, and you'd get live TV. Of course, many, many innovations occurred during that time, but fundamentally, you'd still have a working set.

I do get your point and agree with it.
Right, I see - we lost the VHF TV service in the mid 1980's, so it was different over here. People had to get a new telly then!
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Old February 24th, 2010, 05:00 PM   #19
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Interestingly enough, I found the following link from a photography forum, which probably is one of the reasons why we're seeing this scaling problem with certain/most software.

Gamma error in picture scaling

The worse case scenario image here is certainly a problem on Adobe PSE 7.0, it goes completely gray when I scale it down by 50%. On Premiere Elements 7.0, it gets _ugly_ with pink and green stripes when scaled down to 50%.

It would seem that the same algorithms are still in use.
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Old February 24th, 2010, 06:24 PM   #20
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Originally Posted by Rainer Listing View Post
Thanks Tony, me too (apart from selling thousands of dvds). What I do not understand is how (all else being equal) downresd footage can look better than footage shot at the delivery resolution. I can readily understand why downresd footage would not look as good. If anyone has an objective rational explanation I would really like to hear it.
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Old February 24th, 2010, 06:32 PM   #21
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Originally Posted by Tony Davies-Patrick View Post
That is certainly not true when both are compressed to fit around 1-hour of highest possible quality mpeg2 files on a DVD disc.

That is why I MUCH prefer to use an XL2 compared to an XL-H1 if the final material is only for DVD disc (and I produce and sell thousands of DVDs, so always try to produce highest possible quality).
How did you test it? I am still an engineer at heart and I am curious what your methodology was.

And the reason I have doubts from a practical perspective, is that based on your statements, and the assertions of others, the higher the resolution of the source, the worse the DVD should be. And yet, when I look at material captured on 65mm or 70mm, and watch the DVD derived from that material, it looks better that material derived from S35, 16mm, HD, HDV, or SD.

Similarly, Material sourced from 4k or 6-8K scans should show similar issues when 1080p is the delivery medium, and quite frankly, the IMAX sourced material I have seen on BluRay is just STUNNING. As I would expect, but which runs counter to your assertion.

SO I don't know. My observation of these downscales done with professional, high quality tools, seems to run counter to your assertions, but your observations of materia done with whatever equipment you have available seem to support your assertions.

It's an interesting circumstance, no doubt.
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Old February 24th, 2010, 09:38 PM   #22
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hi Perrone, there seem to be assertions based on subjective observations on both sides. It does not follow that higher resolution leads to poorer quality when downsized, the higher the resolution, the better the approximation (but its still an approximation). I'm thinking the chroma has substantial impact on the viewing experience, and if you can retain this, which you probably can with good encoders, you get more with HD. As to image definition, my analysis tells me you can't improve it by downresing (but if you can someone really should come up with an explanation or test this more scientifically).
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Old February 24th, 2010, 09:51 PM   #23
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As to image definition, my analysis tells me you can't improve it by downresing (but if you can someone really should come up with an explanation or test this more scientifically).
I don't think it can be improved whatsoever. BUT I do believe it can be preserved. If you are shooting with a camera that can resolve 1300lpi (say a Viper) and on the other hand you are shooting with a camera that resolves 400 lines (like the DVX) then by my testing and my eye, the downressed Viper image is going to look superior at 720x480.

The problem(s) I see in this chain is that you've got two really weak areas in the consumer space. The first is that the NLEs typically do a poor job on the downscale. And the second is that the mpeg2 encoders are generally rather poor as well. Combine the two, and it's very easy to conclude that downscaling HD to DVD is not as good as starting with SD. Get both those things in order, and the efficacy of shooting HD for SD delivery starts to show.
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Old February 25th, 2010, 05:24 AM   #24
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Perrone, on this note we'll just have to agree to disagree.

If I thought there was any sense in me using my HD equipment to produce higher quality SD movies on normal SD DVDs then I would definitely be using HD files all the time as the main source.

Not only is it easier to use and edit from main SD source material but the end result to my eyes and most others that I know in the field of producing DVDs, is that well-shot footage from an XL2 is about as good as you can get for widescreen 16:9 at 720 X 576 that is compressed to fit on to a DVD disc.

The maximum length of quality XL2 SD 16:9 Pal footage that can fit on a DVD is about 1-hour 10mins, so that makes 1-hour long edited sections perfect for DVD discs without loss of quality. For example, 1-hour 8mins of raw XL2 Avi sound & video files rendered into a video clip is approximately 14.5GB. To fit onto a disc allowing a maximum file size of only 4.7GB, that 14.5GB file is compressed to mpeg2.

Now take an hour long section of full rez HDV footage as a huge digital file and squeeze all that information through a narrow hole via Mpeg2 compression until it is downgraded enough to be no larger than around 4.7GB (most DVD discs actually don't allow full 4.7GB of information to be burned on the disc and so around 4.3-4.5GB is maximum size of file). That drastically downgraded footage is now only SD and bears no relationship to its former HD glory.

Taking away the obvious facts of ease of workload during post-editing, it all comes down to what the human eye sees on a TV screen at a normal comfortable viewing distance when they slot a DVD disc into the DVD player then sit back and enjoy the movie in standard definition. In this respect, providing that movie content is interesting, 100% of the purchasers and viewers of a DVD disc-full of XL2 footage would be happy with, and not question, the actual visual quality.

So in this respect, if I were about to buy equipment solely to produce 16:9 Pal footage that is destined only for normal SD DVD discs, then I would look no further than an XL2 camcorder.
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Old February 25th, 2010, 09:34 AM   #25
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Perrone, on this note we'll just have to agree to disagree.
I certainly have no issues with this at all. I'll address your points here and leave it alone.

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Originally Posted by Tony Davies-Patrick View Post
If I thought there was any sense in me using my HD equipment to produce higher quality SD movies on normal SD DVDs then I would definitely be using HD files all the time as the main source.
Understood. And it seems clear that using your end to end methodology, it may not be possible for you to create better material with your current equipment.

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Originally Posted by Tony Davies-Patrick View Post
The maximum length of quality XL2 SD 16:9 Pal footage that can fit on a DVD is about 1-hour 10mins, so that makes 1-hour long edited sections perfect for DVD discs without loss of quality. For example, 1-hour 8mins of raw XL2 Avi sound & video files rendered into a video clip is approximately 14.5GB. To fit onto a disc allowing a maximum file size of only 4.7GB, that 14.5GB file is compressed to mpeg2.
Ok, I'm with you so far.

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Originally Posted by Tony Davies-Patrick View Post
Now take an hour long section of full rez HDV footage as a huge digital file and squeeze all that information through a narrow hole via Mpeg2 compression until it is downgraded enough to be no larger than around 4.7GB (most DVD discs actually don't allow full 4.7GB of information to be burned on the disc and so around 4.3-4.5GB is maximum size of file). That drastically downgraded footage is now only SD and bears no relationship to its former HD glory.
Do you realize that HDV is recorded at the same bitrate as DV? Thus the 1hr long file from both cameras will be essentially the same size? This is why HDV uses the same tape as DV. A 1hr DV tape is a 1hr HDV tape, because they are recording the same amount of matieral.

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Originally Posted by Tony Davies-Patrick View Post
Taking away the obvious facts of ease of workload during post-editing, it all comes down to what the human eye sees on a TV screen at a normal comfortable viewing distance when they slot a DVD disc into the DVD player then sit back and enjoy the movie in standard definition. In this respect, providing that movie content is interesting, 100% of the purchasers and viewers of a DVD disc-full of XL2 footage would be happy with, and not question, the actual visual quality.
Well, I don't know that the "ease of workload in post" is obvious. That is quite dependent on what you edit with. On any of my edit machines there is no difference between editing HDV or DV. Both move at real time, and both render at ~2.5x real time. This is logical to me because both are using the same bandwidth. But your point about watching the footage from normal viewing distances is not lost on me. I rather agree. If it is more painful for you to edit and produce SD DVDs from your equipment, and you have no compelling reason to do so, then it seems a waste to do it that way.

There are those who would say that for the purposes of being able to provide HD versions in the future to the same client, it might be nice to have the highest quality master available, but that's a call for you alone to make.

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Originally Posted by Tony Davies-Patrick View Post
So in this respect, if I were about to buy equipment solely to produce 16:9 Pal footage that is destined only for normal SD DVD discs, then I would look no further than an XL2 camcorder.
A logical conclusion.
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Old February 25th, 2010, 09:45 AM   #26
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Originally Posted by Tony Davies-Patrick View Post
Perrone, on this note we'll just have to agree to disagree.

If I thought there was any sense in me using my HD equipment to produce higher quality SD movies on normal SD DVDs then I would definitely be using HD files all the time as the main source.

Not only is it easier to use and edit from main SD source material but the end result to my eyes and most others that I know in the field of producing DVDs, is that well-shot footage from an XL2 is about as good as you can get for widescreen 16:9 at 720 X 576 that is compressed to fit on to a DVD disc.

The maximum length of quality XL2 SD 16:9 Pal footage that can fit on a DVD is about 1-hour 10mins, so that makes 1-hour long edited sections perfect for DVD discs without loss of quality. For example, 1-hour 8mins of raw XL2 Avi sound & video files rendered into a video clip is approximately 14.5GB. To fit onto a disc allowing a maximum file size of only 4.7GB, that 14.5GB file is compressed to mpeg2.

Now take an hour long section of full rez HDV footage as a huge digital file and squeeze all that information through a narrow hole via Mpeg2 compression until it is downgraded enough to be no larger than around 4.7GB (most DVD discs actually don't allow full 4.7GB of information to be burned on the disc and so around 4.3-4.5GB is maximum size of file). That drastically downgraded footage is now only SD and bears no relationship to its former HD glory.

Taking away the obvious facts of ease of workload during post-editing, it all comes down to what the human eye sees on a TV screen at a normal comfortable viewing distance when they slot a DVD disc into the DVD player then sit back and enjoy the movie in standard definition. In this respect, providing that movie content is interesting, 100% of the purchasers and viewers of a DVD disc-full of XL2 footage would be happy with, and not question, the actual visual quality.

So in this respect, if I were about to buy equipment solely to produce 16:9 Pal footage that is destined only for normal SD DVD discs, then I would look no further than an XL2 camcorder.
Tony - IMO, you logic is somewhat flawed.

You haven't taken into account the economics of HDTV's dropping in price - thus providing a larger screen to magnify your lowered resolution SD content as compared to an HD signal being played thru the TV.

Blu-Ray players are predicted to come down in price substantially this year - some to within $150 USD by Christmas 2010. Add to that the falling prices of BLu-Ray burners and media, there is no compelling reason to stay with SD unless you're delivering 720x406 Web rez content.

I'd much rather have to throw away pixels than try to uprez SD footage to HD - which looks like crap in most cases.

Even single chip AVCHD/HDV cameras provide superior rez to any 3 chip SD camera - like the analogy of 35mm film to 4x5 -blow them up to 16x20 - which one will have superior image quality at normal viewing distance?

The viewing public is becoming more visually literate - we are a video generation now.

Staying with SD IMO is career suicide
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Old February 25th, 2010, 12:24 PM   #27
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I gotta side with Perrone. The rest of youse is comparing apples to rutabegas.

Perrone specifically mentions what type of downsizing he is using. The other guys?

I'll agree it is a totaly mystery that most (all?) commonly available programs don't offer high quality downscaling--especially Canopus who built their reputation on high quality codecs. And quite ironic that the program that does it well is shareware. Some kind of consipiracy to make pure HD delivery look better?
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Old February 25th, 2010, 12:56 PM   #28
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Cliff, nowhere have I mentioned that I or others should ignore HD. I work with HD and own HD equipment.
What is in discussion is the fact that when I want to produce highest possible SD DVDs, I don't need to use my HD equipment, because the XL2 matches anything a HD camera can produce on a 1-hour long DVD.

For Blue Ray discs, I most certainly use my HD cameras and lenses.
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Old February 25th, 2010, 03:11 PM   #29
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when I want to produce highest possible SD DVDs, I don't need to use my HD equipment, because the XL2 matches anything a HD camera can produce on a 1-hour long DVD.
A neat summary. On which I think we now have general agreement. And I can't help saying this was my initial point. And as to the price of Blu-ray and media being affordable next Christmas, maybe. I can recall similar comments relating to last Christmas, and the Christmas before, and (my memory is getting hazy but probably) the Christmas before that. I guess it must come one day, just noting that it isn't here yet.
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Old February 25th, 2010, 03:25 PM   #30
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And as to the price of Blu-ray and media being affordable next Christmas, maybe. I can recall similar comments relating to last Christmas, and the Christmas before, and (my memory is getting hazy but probably) the Christmas before that. I guess it must come one day, just noting that it isn't here yet.
I am not sure what "affordable" is. Maybe if you could quantify what pricing is affordable.

I was looking around today for a friend who's interested in Blu-Ray production and the prices I found looked like:

Samsung Blu-Ray player $89.
LG BluRay Burner $108
25GB BluRay discs $2.75

I wasn't able to buy a DVD player under $100 until quite recently. None of the DVD burners I purchased have EVER been below $150, and 25GB BluRay discs are cheaper than the miniDV tapes I last purchased. I adopted BluRay in mid 2008. My current costs to produce a BluRay are cheaper than my costs to produce a DVD when I made the move in mid-2008.

So, at what point do you call it "affordable"?
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