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Old March 21st, 2007, 08:24 AM   #1
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24f lower res compared to 24p.

Tests were done with professionals and novices spotting the difference. A last, this will do away with the myth that there is no discernible difference between 24p and 24f.


Summary:
http://www.freshdv.com/2007/03/what-...a1-camera.html

Article:
http://www.showreel.org/memberarea/article.php?238

Thanks.
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Old March 21st, 2007, 08:51 AM   #2
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Quote:
Originally Posted by Wayne Morellini View Post
Tests were done with professionals and novices spotting the difference. A last, this will do away with the myth that there is no discernible difference between 24p and 24f.
Looking at the article, what they did is compare the Canon 24f mode to footage from a "much pricier" 1080p camera and played it back on a 1920x1080 monitor, at which point there was a 20-25% difference in vertical resolution. Given that the 1080p camera probably cost at least 10-20 times as much as the Canon and that few people currently watch video on 1080p monitors, I'd say that's a pretty good showing for Canon in terms of real-world benefits.

A more interesting comparison would be the Canon XH-A1 in 24f mode against the Sony V1U in 24p mode, so we can see how Sony's approach to 24p from a 960x1080 sensor compares to Canon's approach from a 1440x1080 sensor.
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Old March 21st, 2007, 09:24 AM   #3
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Not again, hasn't it been proven again and again that Canon 24f is not any smart deinterlacing or interpolation?

Canon somehow managed to reclock the ccds to scan progressively (or something like that) despite using interlaced chips.

It is the same as how those CineAlta cams get progressive footages out out interlaced chips.

If Canon only called it 24p in the first place, no one would have even questioned it.
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Old March 21st, 2007, 09:31 AM   #4
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Maybe there is a reason they donīt call it 24P
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Old March 21st, 2007, 11:33 AM   #5
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They don't mention what "much pricier" camera was used for comparison. Particularly without knowing what camera it was, it's a bit of a stretch to draw any conclusions, strictly regarding 24F vs 24P, based on that comparison.
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Old March 21st, 2007, 11:55 AM   #6
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Quote:
Originally Posted by Kevin Shaw View Post
Looking at the article, what they did is compare the Canon 24f mode to footage from a "much pricier" 1080p camera and played it back on a 1920x1080 monitor, at which point there was a 20-25% difference in vertical resolution. Given that the 1080p camera probably cost at least 10-20 times as much as the Canon and that few people currently watch video on 1080p monitors, I'd say that's a pretty good showing for Canon in terms of real-world benefits.

A more interesting comparison would be the Canon XH-A1 in 24f mode against the Sony V1U in 24p mode, so we can see how Sony's approach to 24p from a 960x1080 sensor compares to Canon's approach from a 1440x1080 sensor.
I agree with you, it is an good showing. As 24p is about cinema it can show up even more there.

The pricier camera had it's footage adjusted to remove other bias, and they are both 1080, so should both do 1080 lines.
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Old March 21st, 2007, 12:02 PM   #7
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Quote:
Originally Posted by Vincent Wong Yoon Wei View Post
Not again, hasn't it been proven again and again that Canon 24f is not any smart deinterlacing or interpolation?

Canon somehow managed to reclock the ccds to scan progressively (or something like that) despite using interlaced chips.

It is the same as how those CineAlta cams get progressive footages out out interlaced chips.

If Canon only called it 24p in the first place, no one would have even questioned it.
Vincent, I am interested in what you said, do you have any links to information on this? Is this method they used called summing, which spreads the vertical detail across multiple lines?

There was an method that HV10 people got true progressive, by lowering the exposure to 30th/sec, but you could not have 60th/sec shutter in camera.
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Old March 21st, 2007, 12:41 PM   #8
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If the "much pricier" camera was a CineAlta, it's no surprise that resolution was higher than the H1 (regardless of mode). Take a look at this resolution comparison (about 3/4 down the page):

http://www.adamwilt.com/HD/4cams-part1.html

The H1 shoots a very sharp picture for a camera under 10k, but expecting it to shoot as sharp a picture as a CineAlta is pretty wishful thinking.
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Old March 21st, 2007, 12:48 PM   #9
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Sorry guys, this is old ground, nothing new here. It sure does look like these fellows who did the test really truly gave it a good try, but in the end it is entirely pseudo-scientific...lots of poorly controlled variables and no indication they even used a rez chart at all but rather just took a WAG at the resolution loss. They don't even seem to be aware that at the time of publication of their article, Canon had already said how they do F mode.

Interestingly, at the end of the intro section -- before they even get to the test -- they acknowledge that F mode has superior progressive resolution as compared with other cameras in the price class.

There are already numerous existing threads on DVinfo with more factual info on F mode, mostly in the XL H1 and XH fora. Please do read those threads and contribute to them if you have additional factual info. Given the existence of so many F mode threads, I'm going to close this one.
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