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Glitches occurring in raw XDCam EX1 vision

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Tom David
Glitches occurring in raw XDCam EX1 vision
on Oct 1, 2009 at 5:06:55 am

Hi there,

I have shot over 800 hundred hours with a particular EX1 camera that has started producing a rare glitch in various parts of the footage - one every ten hours worth of raw footage - though still across the odd critical clip for an edit. We are shooting in normal temperatures when the glitches occur.

An example can be downloaded here (22MB of raw XDCam footage).
https://rcpt.yousendit.com/747777967/a49f4db49e01a3b4573171c0df0530e4

I would be grateful if anyone with some knowledge of glitches in raw video and is interested taking a quick look - it isn't occurring regularly enough to be able to replicate in front of the Sony techs here in Melbourne.

Cheers,
Tom

Camera Operator - Editor - Motion Graphics
(http://www.tomdavid.com.au)


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Noah Kadner
Re: Glitches occurring in raw XDCam EX1 vision
on Oct 1, 2009 at 1:40:56 pm

If you've shot 800 hours I'd strongly suspect the camera is due for a complete servicing. And wouldn't it make sense to show this glitch clip to the Sony techs?

Noah

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Tom David
Re: Glitches occurring in raw XDCam EX1 vision
on Oct 1, 2009 at 11:26:28 pm

Thanks Noah,

The camera was serviced over a month ago now however its not until now that we are editing this particular footage. So I am not sure if recent software upgrades etc correct this issue yet.

Though I will always post my questions for feedback in this forum before I hand over my cameras back to the techs for four weeks - in the past this has saved me a lot of time!

Cheers,
Tom

Camera Operator - Editor - Motion Graphics
(http://www.tomdavid.com.au)


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Rafael Amador
Re: Glitches occurring in raw XDCam EX1 vision
on Oct 1, 2009 at 2:31:42 pm

Hi Tom,
I've been making some simple test with the clip.
My gear is limited, but with the Apple Colors video-scope is possible to have a look to the Components.
I've just cropped the picture letting only the lower band.
Comparing the wrong frame with the one before and after, is easy to see that there is a levels drop in the three components: Y', Cb and Cr.

If you have a look to the Parade, you see that while the Red Channel drops a lot, the Green Channel drops just a little, and the Blue Channel go a bit up.

So in may poor knowledge, there is something wrong after the RGB signal have passed the matrix and converted in Y'CbCr.
Is not a problem of reading the CMOS, but after.
If it would be a consistent drop in RGB, could be corrected and that correction should work on all the frames with the same issue.
being the drop in the Y"CbCr channels is much more complicated to correct. Each wrong frame would need a different correction.
I guess this is not of much help for you anyway.
Rafael

http://www.nagavideo.com


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Michael Palmer
Re: Glitches occurring in raw XDCam EX1 vision
on Oct 1, 2009 at 3:09:16 pm

Hopefully this is an isolated case and Sony replaces or repairs the camera.

I don't believe a solid state camera should ever need servicing for this type of issue, but it would be good to know if you have presented this clip to your Sony representatives and let us know what steps they are taking to fix it.

I would like to know what you have been using to power this camera, (batteries/AC) and have you checked the condition of your batteries and could this issue possibly be related to the power supply being interrupted.

Also are you only using SxS cards? It seems the sensors failed to offload the data.

Good Luck
Michael Palmer


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Denis Devlin
Re: Glitches occurring in raw XDCam EX1 vision
on Oct 1, 2009 at 5:34:54 pm

I have experienced a more severe "glitch" as documented here:

http://forums.creativecow.net/thread/142/863389#863397

(follow the links if you want to see the footage - 11.5 Meg).

Its not clear to me if the problem is really similar or not - my example evidently involves several frames. Also, unlike the example above, my equipment was all new. I have not seen the problem occur again since getting a replacement memory card. But it was not a reproducible problem anyway, so its not at all clear that replacing the card is relevant one way or the other - and I am not running the camera for hundreds of hours so the evidence is hard to evaluate.


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Tom David
Re: Glitches occurring in raw XDCam EX1 vision
on Oct 1, 2009 at 11:51:25 pm

Thanks guys, I appreciate the feedback. As mentioned to Noah, the camera was serviced a month ago, though it is only now that our editors found the glitch working back through the footage. So I am not sure if this has been naturally corrected in the service with software upgrades etc.

Rafael, thanks for your thorough look at the signal - an insight into where in the camera system the problem might occur. Thankfully this occurred in a still lower portion of screen, so we could duplicate that portion from frame before, problem solved - in this case.

Michael, not so isolated -I have seen this with Panasonic cameras - an HPX3000 was playing up and glitching regularly - we handed over to the techs who were able to replicate and the guts of the camera were replaced. The liver? The lungs? I wasn't sure. In the case of the EX1, we were shooting with batteries that appear in good condition, and haven't let us down since.

Dennis, owch... Your type of problem would really have had me worried! I have not come across that before, though the replacement outcome would have been appreciated.

Thanks team, will let you know if I ever solve the problem.

Cheers,
Tom

Camera Operator - Editor - Motion Graphics
(http://www.tomdavid.com.au)


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