Black shimmering pixels in highlights on BMPC

Hi

Shooting some interviews & record of event stuff last week with our BMPC and started experiencing black speckled noise in the highlights... As demonstrated here...



I'm aware of the purple highlight thing, and I went into shooting this being aware bright stage lights were probably going to suffer from this, but I didn't expect black shimmery pixels... You'll also notice in this sample video, there is some green shimmering pixels as well.

I've got the latest firmware and I've tried looking on the web for answers, but everything tends to be about the purple highlight, not black noise...

Any thoughts would be greatly appreciated!

Thanks,
Chris

That's the Blackhole Issue. It tends to display itself over clipped highlights.

Shooting some interviews & record of event stuff last week with our BMPC and started experiencing black speckled noise in the highlights... As demonstrated here... [...] I'm aware of the purple highlight thing...

Just to clarify: are you talking about the 4k production camera (BMPC) or the HD pocket cinema camera (BMPCC)? The "purple highlight thing" is an issue found only in the pocket cinema camera, as far as i know it doesn't present in either of BMDs other cameras. On the other hand the pocket cinema camera is the only one that does not suffer from the "black dots in higlights" issue that all other cameras show when overexposed. In both cases we expect BMD to provide a fix, but have been waiting for a long time now...

[Jason Munn]

Hi Chris,

Can you tell us the camera software version you are using and your post production workflow? For example, the software you edited/exported your sample footage with?

Also, can you describe the recording format for your sample footage? For example 2.5K RAW, ProRes or DNxHD.

Try reproducing the effect with your camera. If you can, describe how you did it - we can then reproduce the effect here and learn what it is.

Can you also send us the original camera files via Dropbox or something similar.

Last question - where are you located, Chris?

Best regards,

Jason

Also, can you describe the recording format for your sample footage? For example 2.5K RAW, ProRes or DNxHD.

It was shot on the BMPC - it only shoots ProRes at the moment.

This is strange,

I have seen this happen when I have clipped whites in Adobe After Effects and rendered it out to DNxHD. It doesn't appear in the original file only when rendered out. But I have never seen this in ProRes footage.

http://forums.thefoundry.co.uk/phpBB2/v ... p?t=5888&s

[Jason Munn]

Also, can you describe the recording format for your sample footage? For example 2.5K RAW, ProRes or DNxHD.

It was shot on the BMPC - it only shoots ProRes at the moment.

No worries, Adam. I wasn't sure. Thanks.

Best regards,

Jason

[Jason Munn]

This is strange,

I have seen this happen when I have clipped whites in Adobe After Effects and rendered it out to DNxHD. It doesn't appear in the original file only when rendered out. But I have never seen this in ProRes footage.

http://forums.thefoundry.co.uk/phpBB2/v ... p?t=5888&s

Interesting. If the black pixels do not appear in the original camera files, it looks like the issue may occur in Chris's Post Production workflow. Would be good to learn more so we can confirm this.

Best regards,

Jason