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-   -   Seriously Disturbing - Clip damaged (https://www.dvinfo.net/forum/jvc-gy-hm-150-100-70-series-camera-systems/483079-seriously-disturbing-clip-damaged.html)

Charles Wannop August 8th, 2010 06:16 PM

Seriously Disturbing - Clip damaged
 
I have just finished shooting a two day conference - about 5 hours of sessions per day. I bought two Sandisk 32 gig cards (class 10) a couple of months ago, I added two new ones for this shoot. Day 1 went off fine. I downloaded (via a Sandisk Express reader) and made multiple copies on external disks (and internal drive).
Day 2 I reformatted the SD cards and started shooting. At morning tea break I changed cards and started downloading the first sessions. 329.6 meg into the third clip I got a finder error that the contents could not be read (error code -36) and the card was unmounted. Panic! I found that it was one particular clip that seemed to be the problem, all other clips copied fine. The broken clip would preview fine, I could skip through it and as long as I kept away from 1:19 it would play - something in that region would cause the error code.
I managed to use Mpeg StreamClip to export around the "death-zone" so I have lost only a few seconds of material.
BUT the second card of the day also has a corrupt clip on it and I am about to go through the same process to rescue what I can (these were the cards that I bought a couple of months ago and have used maybe a half dozen times max). The rest of the day went smoothly with the new cards and I *think* I am going to be able to get away with it but this has really shaken my confidence in shooting to SDHC.

Charles.

Chris Soucy August 9th, 2010 01:08 AM

Hi Charles............
 
Given the shoot time, I'm assuming you were shooting using mains power?

If that is the case, were you using a UPS to keep things running sweet?

May sound daft, but what you're humping around there is a computer with some expensive glass tacked on the front, they don't like dodgy electric supplies.

It may be the cards, but given Canberras' rather eccentric electric supply system, it may well not be.

A power glitch of even a microsecond could be enough to affect a data write, and they get them there all the time.

I would try the affected cards again using battery to see if the problem can be replicated, if not, get an easily portable (is there any such thing?) UPS system to feed the camera(s) if used again under similar circumstances.

Don't blame the messenger till proved guilty!


CS

Charles Wannop August 9th, 2010 03:00 AM

Interesting idea Chris... I assumed (yeah I know :-)) that having the battery in place while running on mains would give me some protection from spikes and glitches. I was shooting on the Gold Coast but I would think that their power is just as flakey as Canberra so the ups idea is a good one.

Thanks,

Charles.

Chris Soucy August 9th, 2010 09:32 PM

Maybe.............
 
Something like this, perhaps?

http://www.upspower.co.nz/documentat...ev27054405.pdf

It would have the other major advantage of allowing you to effectively run "on battery" for absolutely ages, no mains required.

Just a thought.

CS

Charles Wannop August 11th, 2010 12:03 AM

More testing....
 
At Sandisk's suggestion I re-formatted both cards and left the camera recording on the table for anywhere between 10min and 1h53 in an attempt to re-create the error. After a few tries I was able to get both cards to error again (twice), then just as I was getting ready to send them off to Sandisk for replacement I tried one on the new cards - it failed too!!!!!
I am now testing my 16GB cards (all the others were 32GB). I still have this sinking feeling....


Charles.

Chris Soucy August 11th, 2010 02:38 AM

Uh.....................
 
You running the camera on battery or mains?


CS

Charles Wannop August 11th, 2010 03:09 AM

Hmm still mains... but I tried intentionally played with the mains lead (half pulled out so it made nasty sparking noises) which put interference on the picture (both on the viewfinder and then on playback) and all was fine.... still testing...

c

Marty Mulholland August 12th, 2010 06:00 AM

sorry to hear that! lots of shoots i've done recently have been long ones (conferences etc) and i've been using the 16gig sandisk class 6 cards that came with the camera

since then i've purchased some class 10 cards (also 16gig) and have yet to have an issue but i'll be keen to know what your problem is so keep us posted!

Charles Wannop August 13th, 2010 01:06 AM

Solved!!
 
Ok, this is going to take a bit of explaining, so just bear with me ☺

As I reported earlier, after 13 months of happy operation, I started to get clips that were damaged out of the HM-100. The damage meant that the clip would not transfer to the host (Mac or PC) on the Mac it caused the SD card to un-mount during the read/copy process. The clip looked all right and could be ‘quick looked’ safely, right up to the point of damage. Using MPEG Streamclip I was able export ‘around’ the site and so didn’t loose anything crucial…this time. It seemed to always be a single clip that was damaged, so less than a second’s corruption on a 1h53min card. I finally found a pattern and was able to reproduce the fault. It comes back to using the Mac to erase the card using the Disk Utility (I realize this might sound like a dumb thing to do – but as they say “It seemed like a good idea at the time). So…

1) Erase card using Disk Utility
2) Insert card into HM-100
3) HM-100 wants to re-format – Say ‘Yes’
4) Card *may* reformat OK, or show an error, if so I formatted again in the camera
5) Either way, use card as normal – No error codes reported during shooting.

Now the crazy stuff, cards that showed the error worked perfectly, cards that re-formatted ‘correctly’ the first time ended up with clip damage. Damaged cards reformatted in the HM-100 worked perfectly subsequently.

If the card is erased in the Mac (haven’t been able to test on a PC) you must re-format it TWICE in the camera to avoid ending up with one clip on the card being damaged.

So the good news is that both camera and cards are alive and well and I can relax again.


Charles.

PS - I did buy a UPS just in case, and I will be able to use it with my KiPro so it is not a wasted effort. BUT Chris, no-go on running the UPS as a big battery supply - it beeps VERY loudly every 30 seconds or so to tell you that the mains is out :-)

Steve Cottrell August 14th, 2010 11:52 AM

On a point of information, since I purchased a Canon D60 DSLR (that's right - the one after the D30, we're talking ancient history here) I was told to only format the card in the camera and never a PC (or Mac in my case). Once I have downloaded clips from SDHC into the Mac, I just take out the SDHC card from the SDHC/PC Card adapter and pop it back into the HM100 and format the card(s). Never had a problem. HTH Cheers.

Marty Mulholland August 15th, 2010 08:16 AM

i used the mac to reformat once in order to name the cards (card1,2,3 etc) but after formatting the card again in the camera, we were back to untitled 1 so from then on i never bothered trying to do it in the mac again

glad you solved it and the camera is working as it should :)


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