BMPCC gradient sensor noise

The place for questions about shooting with Blackmagic Cameras.
  • Author
  • Message
Offline

Ales Kubovic

  • Posts: 30
  • Joined: Sat Jul 14, 2018 1:41 pm
  • Location: Czech Republic
  • Real Name: Ales Kubovic

BMPCC gradient sensor noise

PostSat Jul 14, 2018 2:02 pm

Hello,

I want to ask if the sensor in my Pocket camera is OK. If I upload a black record (with lens cap) and in Davinci Resolve press Alt+A, it will become what you can see in my picture.

bmpcc_1.1.1.jpg
BMPCC noise
bmpcc_1.1.1.jpg (674.69 KiB) Viewed 567 times


Thank you very much!

(sorry for my bad google english)

Ales K.
Offline

Ales Kubovic

  • Posts: 30
  • Joined: Sat Jul 14, 2018 1:41 pm
  • Location: Czech Republic
  • Real Name: Ales Kubovic

Re: BMPCC gradient sensor noise

PostMon Jul 16, 2018 4:30 pm

Maybe heatsink?
Offline
User avatar

Daniel Bănică

  • Posts: 128
  • Joined: Thu Oct 13, 2016 10:56 am
  • Location: Poland

Re: BMPCC gradient sensor noise

PostMon Jul 16, 2018 9:23 pm

Show us what the scopes are saying
Offline

Ryan Payne

  • Posts: 264
  • Joined: Sat Apr 15, 2017 6:48 am

Re: BMPCC gradient sensor noise

PostMon Jul 16, 2018 10:22 pm

Is this corrected or out of camera?
Offline

Anatoly Mashanov

  • Posts: 518
  • Joined: Sun Sep 28, 2014 11:36 am
  • Location: Russia

Re: BMPCC gradient sensor noise

PostTue Jul 17, 2018 2:44 am

Turn the camera off, let it cool, then turn on and immediately make a test shot. If the gradient disappears then it looks to be a heat sink problem. Then it could be necessary to add a thermal paste under a cryo device and under both ends of heat pipes and/or add an additional copper heat spreader under a cryo device.

Also for some scientific study it would be nice to allow the camera to be pre-heated upside down and make another test shot.
Offline

Ales Kubovic

  • Posts: 30
  • Joined: Sat Jul 14, 2018 1:41 pm
  • Location: Czech Republic
  • Real Name: Ales Kubovic

Re: BMPCC gradient sensor noise

PostTue Jul 17, 2018 4:04 am

This is a recording when the camera is turned on, so the camera is cold. In normal use, this is fine, only some hot pixels appear occasionally, but I think it's normal.
This is a very gain footage (using the keyboard shortcut Alt + A).

I only wonder if this uneven noise distribution is the property of the camera. Can someone please try a black footage(from BMPCC) in Davinci Resolve using Alt + A (Auto Contrast)?

If it is not normal that the upper part of the sensor noise a little bit more, it might mean that noise could be reduced by adjusting the heatsink. It could be a bit less noise when low-light recording.

Once again, I say that this is not visible in a normal footage.

Sorry for my english folks, and thank you! :)

Return to Cinematography

Who is online

Users browsing this forum: Poozon and 117 guests