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-   -   16 gb card recording time (https://www.dvinfo.net/forum/canon-xf-series-4k-hd-camcorders/499687-16-gb-card-recording-time.html)

Vincent Oliver October 14th, 2011 03:08 AM

Re: 16 gb card recording time
 
Glad you like the camera Gareth. I presume you haven't got any yellow burn marks in your viewfinder (YET)

Gareth Burleigh October 14th, 2011 12:28 PM

Re: 16 gb card recording time
 
No not yet and its been used heavily since it was bought a couple months ago. Is it a common fault?

Vincent Oliver October 14th, 2011 12:49 PM

Re: 16 gb card recording time
 
Maybe Canon have fixed the problem, by fitting a new viewfinder, I haven't seen a new model as yet. My one developed the problem on its first day out and has had a second helping more recently. Take a look at this post

http://www.dvinfo.net/forum/canon-xf...05-owners.html

Gareth Burleigh October 14th, 2011 04:31 PM

Re: 16 gb card recording time
 
Ouch that isn't good, I'll be sure to keep a look out for it. Did Canon get this sorted for you?

Vincent Oliver October 15th, 2011 12:55 AM

Re: 16 gb card recording time
 
No I haven't had the time to send it off. I use my Sony EX3 most of the time

Gareth Burleigh October 15th, 2011 02:06 AM

Re: 16 gb card recording time
 
Im sure I had something similar happen to an old Sony VX, I just put it down to wear and tear. Saying that, that poor cam saw more wear and tear than most

Martin Doppelbauer October 18th, 2011 02:24 PM

Re: 16 gb card recording time
 
Please forgive me for coming back to the original topic of this thread ;-)

In the meantime I was able to run a couple more tests.
Firstly, the memory that is reported "unused" on the cards is really freely available. I can copy any file on it (on my computer) and read it back without problems.
Secondly, when I record just ONE very long clip onto a newly initialized card it really uses (almost) all of the available space (up 56 mins and 45 secs on a 16 GB card to be precise).

Finally, I sent one of the cards to Canon service and after two weeks they returned it claiming all was ok and the behavior would be perfectly fine. They didn't offer a technical explanation, though.

My theory is, the Camera will only start recording a new clip on an "aligned" block address, probably to make maximum use of the memory block transfer feature of CF specification 5.0 (compact flash cards are accessed just like IDE hard drives using logical block addresses LBAs). In most cases, that would leave an unused gap between the blocks taken up by two consecutive clips (depending on the length of the first clip, of course).

Adding up the number of clips and all of the unused space of my twelve cards computes to a gap of 80 MBytes per clip, which should be more or less a constant for the average of a large number of clips.

When recording just some very few (long) clips onto a card, those 80 MBytes per clip wouldn't be a significant number. But in my way of recording a lot of 15 to 30 seconds clips, these losses add up considerably.
I am not too happy about loosing some 20% of the valuable capacity of those expensive CF cards but it seems that is considered "normal behavior" by Canon.
Just wondering if Sony or the others have a similar problem...


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