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-   -   7D maximum sustained recording length? (https://www.dvinfo.net/forum/canon-eos-crop-sensor-hd/355721-7d-maximum-sustained-recording-length.html)

Jeff Wisener October 20th, 2009 03:26 PM

Hmm, not sure who is right on this one. I thought the length of the recording time was limited to cool the sensors.

Alex Leith October 20th, 2009 04:52 PM

Quote:

Originally Posted by Jeff Wisener (Post 1435405)
Hmm, not sure who is right on this one. I thought the length of the recording time was limited to cool the sensors.

If that were the only reason then I would think 1080 720 and 480 would all have the same limitation.

Robert Davis March 3rd, 2010 11:37 AM

Quote:

Originally Posted by Phil Hover (Post 1306674)
the gh1 is a better option for long recording.

In what way? :-
- unlimited recording length? (only restricted by size of card?)
- 1920x1080p at 24p for easier compatibility for archiving to blu-ray?
- better quality?

Link to Panasonic GH1 micro-DSLR camera here:
http://www.panasonic.co.uk/html/en_G...697/index.html

Robert Davis March 3rd, 2010 11:41 AM

FAT32 limit? then why do PVRs, blu-ray players manage many gigabytes of data?
 
Why would the recording limit be due to FAT32 maximum file size?

DVD players, Blu-ray players, Personal Video recorders all cope with material that, in total, is larger than the FAT32 limit. Either by using a suitable file system that can cope with >FAT32 file size limit or by breaking the material up into several files but being able to play them contiguously, seamlessly, back-to-back flawlessly.

Chris Hurd March 3rd, 2010 12:09 PM

Quote:

Originally Posted by Rob Davis (Post 1494298)
Why would the recording limit be due to FAT32 maximum file size?

It's important to understand that the recording limit is not due to FAT32 maximum file size.

Jesse Haycraft March 3rd, 2010 11:28 PM

Chris, everything I have seen both from my own experiences and what I've read of others indicates that it is in fact the FAT32 limitation working here. Could you perhaps elaborate on why you disagree with that?

Robert Davis March 5th, 2010 06:47 AM

Let's have a definitive answer from Canon, please
 
Quote:

Originally Posted by Chris Hurd (Post 1494313)
It's important to understand that the recording limit is not due to FAT32 maximum file size.

Well, what is it precisely, then?

Tell you what, I would go to a trade/consumer fair and go to the Canon stand and ask them direct or call or email - to get a definitive answer... rather than speculating here! Oh (I know you might not have) my recommendation is don't ask a newbie junior salesperson, ask someone more senior with them who really knows.

Again, to re-iterate, if the limit was FAT32 4Gb then why can Television Program Personal Video Recorders and Blu-ray players handle longer lengths e.g. 25Gb? Either because they use another file system or break the recordings up into several files BUT employ a system to provide seamless, back-to-back flawless recording/playback of these files, perhaps enabled by some sort of playlist table file.

If it is a futile EU/EC ruling about it being a camcorder of it records longer, incurring an extra duty/tax then the EU/EC people need to campaigned against because the convergence between moving and still technologies is inevitable. they both use CMOS or whatever sensors, lenses, memory cards. If you can take beautiful stills then why not be able to take beautiful quality moving pictures with the same camera?

Quote:

Originally Posted by Christopher Lovenguth (Post 1311541)
Canon was not thinking of this as a video camera, it is a still camera in their mindset with video option.

Faulty thinking on Canon's part: Again to repeat, the convergence between moving and still technologies is inevitable. they both use CMOS or whatever sensors, lenses, memory cards. If you can take beautiful stills then why not be able to take beautiful quality moving pictures with the same camera?

Cameras such as these will cannibalise the camcorder market. And so what? Why make an artificial divide: a camera is a camera is a camera! Let market disruption proceed. In this digital multimedia age people are doing both moving and still and don't want to carry both around.

What a shame about this limit. If only it wasn't there then this camera would be a fantastic all-rounder and a contender for making proper decent film footage with the flexibility of SLR lenses providing all manner of filmic nuances and quality.

Length should only be limited by size of memory card.

Robert Davis March 5th, 2010 02:35 PM

4th reason: this 7d camera would damage pro sales if unlimited recording limit
 
4th reason added to my three mentioned above: this 7d camera is a disruptive breakthrough technology and impacts existing established systems in the market.

There is perhaps *absolutely* NO reason why the 7d dslr camera could not record continuously, back-to-back, seamlessly footage beyond the 1080p 12mins FAT32/4gb limit.

As stated before, it could split the files and apply a separate playlist table file to enable seamless back-to-back recording/playback to overcome the FAT32 limitation and therefore enable a continuous uninterrupted recording way beyond the approx fat32 4gb/12min 1080p limit.

The real reason might be that if Canon enabled unlimited recording, then this would impact sales of higher-end professional broadcast cameras that don't offer much more quality than the 7d.

Barry Green March 6th, 2010 03:15 PM

Quote:

Originally Posted by Jesse Haycraft (Post 1494612)
Chris, everything I have seen both from my own experiences and what I've read of others indicates that it is in fact the FAT32 limitation working here. Could you perhaps elaborate on why you disagree with that?

I'm not Chris, but I can answer -- because P2 uses the FAT32 file format, and you can record continuously for hours or even days with it. And AVCHD uses the FAT32 file format, and it can record for 12 continuous hours on a single card.

It's true that FAT32 has a 4GB file limit, and it's true that the Canons stop recording at 4GB. But why don't they just span clips, like AVCHD and P2 do? It's not the file system that's causing the limitation. It's the fact that they don't span clips to get past the file system's maximum size.

Either a) they just didn't want to bother, or b) perhaps the Quicktime file format they record into, doesn't allow for chaining clips and pointing to previous and next clips.

Either way, the limitation isn't because of FAT32, because other manufacturers and systems have successfully gotten around that.

Christopher Drews March 6th, 2010 05:14 PM

It's all about the HEAT, baby.
 
My camera has never overheated *just* taking stills.
Canon would have to spend more in R&D to address the overheating issues. The file size limitations cool the camera. This problem seems to be linked to shooting HD video (never had issues with SD heat warning).

This all seems like conjecture though (my thought included)...

Why do Toyotas accelerate without driver intervention?
Is it the floor mats or the electrical system?

-C

Jesse Haycraft March 8th, 2010 03:12 PM

Quote:

Originally Posted by Barry Green (Post 1495901)
I'm not Chris, but I can answer -- because P2 uses the FAT32 file format, and you can record continuously for hours or even days with it. And AVCHD uses the FAT32 file format, and it can record for 12 continuous hours on a single card.

It's true that FAT32 has a 4GB file limit, and it's true that the Canons stop recording at 4GB. But why don't they just span clips, like AVCHD and P2 do? It's not the file system that's causing the limitation. It's the fact that they don't span clips to get past the file system's maximum size.

Either a) they just didn't want to bother, or b) perhaps the Quicktime file format they record into, doesn't allow for chaining clips and pointing to previous and next clips.

Either way, the limitation isn't because of FAT32, because other manufacturers and systems have successfully gotten around that.

In other words, yes, it is because of the fact that it's FAT32. All that other stuff about Canon not bothering to get past that limitation doesn't matter, because it's still FAT32 which created the limitation. So yes, it is because of FAT32.

Jon Fairhurst March 8th, 2010 06:57 PM

Jesse,

You are right that FAT32 limits the size of each file, but some cameras start a new file automatically without any gap between clips. Stitch them together and you can get a long take.

Presumably, the reason that Canon doesn't do that is that any device that records more than 30 minutes of video is considered a video camera, and in some regions that increases the tariff.

So, FAT32 explains the 4GB per file limit, but not the overall recording limit.

Barry Green March 8th, 2010 07:59 PM

Quote:

Originally Posted by Jesse Haycraft (Post 1496726)
In other words, yes, it is because of the fact that it's FAT32. All that other stuff about Canon not bothering to get past that limitation doesn't matter, because it's still FAT32 which created the limitation. So yes, it is because of FAT32.

You can place the blame wherever you want, but the fact remains that other camera systems use FAT32 and have unlimited recording times. Ergo, de facto, obviously, it is possible to have unlimited recording times on a FAT32 system. Therefore, the limitation is not and cannot be laid solely at the feet of FAT32.

Régine Weinberg March 26th, 2010 07:00 PM

Oh Uh
 
it is fat !! Why Windows is not longer using it, that is the reason as the Canon has this limit ALLL over the world.
Reformated the 4 gb card in my Blackberry with a win format on my linux machine, it works fine but I do get ...mediacard formated with errors. There are no. It is not a proper fat 32.....genuine windows, came out as fat from Debian, but it is not a real win 32 fat....haha.
that I do think is an asnwer.
why a D7 bought in Bangkok has a 4 gig limitation, why a D7 from California has it ?
nothing to to with Europe as they don't realize a customs yet this can do film, it is a stil camara from tax definition, dead easy like the Nikon 3Ds

Kin Lau March 26th, 2010 07:41 PM

The 4gig limit exists because of using 32bit pointers - it actually exists in many places independent of FAT32. FAT32 just happens to be one very well used standard with 32bit pointers and limitations.

Apparently, Quicktime itself has some 4gig limitations as well. Regardless of the file system, exporting a greater than 4gig Mpeg4 QT movie will cause the file to be corrupted.

The Quicktime Mpeg2 decoder also cannot handle > 4gig files. Apple has acknowledge it as a bug.


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