Author Topic: 5D3 raw video - grey pixels at higher ISO?  (Read 4342 times)

MGerard

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5D3 raw video - grey pixels at higher ISO?
« on: March 23, 2014, 11:07:30 AM »
The Magic Lantern raw recording workflow has openend a whole new world for me and it is spectacular to be able to work at such a high level of image quality for filming.

I have spent quite some time and money to find the right cards and workflow to record 1080p without dropouts and more or less process the clips in a reasonable amount of time.

Last week, I went to a bar to shoot a concert of a friend of mine and was faced with a rather dark environment, which forced me to shoot at rather high ISO settings on my 5D3 (ISO1600 - ISO 2000). That was the first time that I realized a number of light grey pixels that appear in dark areas, and I have been testing the camera for this annoyance ever since. It seems that those grey pixels appear at ISOs above 800, taking the long way (ACR) to process the DNGs sometimes takes care of some of them, but not of all and not every time.

Do other users also experience these issues? Any suggestions to get rid of them?

Thank you very much,

Martin

MGerard

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Re: 5D3 raw video - grey pixels at higher ISO?
« Reply #1 on: March 23, 2014, 05:31:00 PM »
To be a bit more specific, here is a link to some examples. The pixel dots stay where they are and move with the camera.
Running the manual cleaning option on the 5D3 does not solve the problem.

https://www.wuala.com/superhypernatural/Clients/ML/?key=J8U7ZlBe3jVU

I would be very thankful about suggestions.

Midphase

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Re: 5D3 raw video - grey pixels at higher ISO?
« Reply #2 on: March 23, 2014, 06:29:43 PM »
I have run into Stuck Pixels issues when pushing ISO past 1600.

It's a real issue which can be a bit problem if you're planning an entire production in low light situations.

You can clean them up fairly simply in AE, this is because the pixels are always in the same exact spot. The Wire removal tool works nicely, but even a blur filter on them will get rid of them. In Resolve you could do the same by making a mask and applying the blur.

The main downside it that it adds a bunch of extra time to your post workflow and it's an eyesore to look at while you edit.

I don't know of any in-camera solution that will fix this issue.

MGerard

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Re: 5D3 raw video - grey pixels at higher ISO?
« Reply #3 on: March 23, 2014, 06:38:20 PM »
Thank you for your answer! Fun thing is, on my camera they seem to appear randomly and not always at the exact spot. I have been trying out a plugin for FCPX and once replicated on a different clip the stuck pixels moved (by one pixel left / right / up / down). Might have something to do with the binning of the full sensor resolution down to 1080p... Would sending the camera to Canon be a solution for the problem? I understand that the raw recorded by ML is direct sensor information, is the re-mapping process before the raw extraction or after? I don't have any issues with the standard h264-recording, but high compression might as well blur the faulty pixels out.

Midphase

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Re: 5D3 raw video - grey pixels at higher ISO?
« Reply #4 on: March 23, 2014, 06:40:55 PM »
Right, if you send the camera out to Canon, they will take photos, and take some video, and they will confirm that everything works as it should even at the highest possible ISO, and send it back to you because there's nothing to fix.

hjfilmspeed

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Re: 5D3 raw video - grey pixels at higher ISO?
« Reply #5 on: March 28, 2014, 05:21:55 AM »
Its funny you say this i have had slight suspicion that these pixels are the very reason why canons h.264 codec is a lil soft. I also wondered if these dead pixels are made more apparent from being down sampled to 1920x1080 in the live view feed and maybe canon said hey put a lil blur in the codec and they go away. Unless i missed something i never understood why the h.264 codec was lacking in detail especially now that we can see the raw feed is sharp. I know the codec compresses things but the all-i should resolve a lil closer to the raw but man is it night n day! The ml raw is sooooo much better so maybe it is just a poor codec. after all where would the cam get extra processing power to add a blur in the mix when the cam is already taxed.

Anyways now that i have finished that rant. It looks like your a fcp user but for a Sony Vegas user reading this, there is a nifty little plug in called pixel patcher that works great for this. Also there was work being done to fix cold pixels in the raw2dng conversion. But for now, just know post will be a bar above iso 1600. try using 3200 + fps override @ 1.5 fps and you will be pixel patching your brains out! Though i still feel the benefits of the raw quality is worth it. I mean the color and the sharpness must be very close or maybe even better then the c300 on the 5d3 now. Thats crazzy to think about! 

Midphase

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Re: 5D3 raw video - grey pixels at higher ISO?
« Reply #6 on: March 28, 2014, 05:58:06 AM »
In all fairness, most sensors are susceptible to stuck pixels, even the high end ones which come equipped on cameras that cost more than my house.