DNG HIGHLIGHTS PROBLEM

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

Andrea Monzini

  • Posts: 97
  • Joined: Tue Jul 15, 2014 10:24 am

Re: DNG HIGHLIGHTS PROBLEM

PostSun Sep 28, 2014 12:09 pm

Iliah Borg wrote:Dear Andrea,

Sorry for the late answer. White level is set close to the linearity limit in highlights, it does not depend on the light but only on the sensor design. Setting the black level is like saying "this is the mark on the bucket, and if the water is on the mark we consider it to be full". However the is sample variation between sensors, so in certain cases even a conservative setting for white level may be too high. The way to avoid the issue is a combination of tighter quality assurance, quality control, individual sensor calibration at the factory, self-calibration in camera. The cost involved is pretty substantial. If the manufacturer understand the issue they may allow the end user to set/adjust the white and black levels.


Thank you for the explanation!
I hope in a firmware update to set the white and black levels.
Meanwhile Exiftool is a good workaround and i am able to use Highlight Recovery without pink grid noise.

You can use Exiftools directly as command line and if you are using a Mac i wrote a very simple applet:

http://andreamonzini.com/files/WhiteLevelTool_BM.zip

This is source code section to open the terminal and set the Whitelevel value:
Code: Select all
   tell application "Terminal"
      reopen
      activate
      
      set results to do script "exiftool -v3 -IFD0:WhiteLevel=" & "" & white & " -ext dng -overwrite_original -r" & " " & theFolder
      
   end tell

I use this Applet as an exiftool GUI solution to set the WhiteLevel.
But of course you can use directly the command line like for example:
Code: Select all
exiftool -v3 -IFD0:WhiteLevel=25000 -ext dng -overwrite_original -r /Users/iMac/Raw*

*Folder Path Example

Where:

-v[NUM] (-verbose) Print verbose messages
-IFD0:WhiteLevel= Set Value for WhiteLevel
-ext EXT (-extension) Process files with specified extension
-overwrite_original Overwrite original by renaming tmp file
-r (-recurse) Recursively process subdirectories

Please check ExifTool website for the use and documentation:

http://www.sno.phy.queensu.ca/~phil/exiftool/

Anyway i contacted Blackmagic support and i hope that this workaround will be soon not necessary to recovery highlights without the risk of Pink grid noise.
Offline
User avatar

Philipp Schröppel

  • Posts: 222
  • Joined: Fri Apr 25, 2014 12:41 pm
  • Location: Potsdam - Germany

Re: DNG HIGHLIGHTS PROBLEM

PostSun Jun 19, 2016 11:34 am

The link is dead. Any chance to upload it again or is there a new way to deal with that problem?
Pete
Offline
User avatar

Andrew Bell

  • Posts: 323
  • Joined: Sun Nov 23, 2014 1:15 am
  • Location: Russian Federation

Re: DNG HIGHLIGHTS PROBLEM

PostSun Jun 19, 2016 1:52 pm

I use the following metod in Resolve now:
1. Turn on the restore highlight checkbox.
2. Tweak the exposure to see the highest highlight data.
3. Tweak the color temp and tint to remove the highlight color artifacts. You should mostly look not to the picture but to the scopes. In right numbers you will see that parade in highlight area becames more linear and less jugged i e without steps. Tint numbers about 55-60 is always help.
4. In the next node you should return the color balance back to normal by using lift gamma gain tweaking.

By this metod I can comletely eliminate the magenta highlights problem and also I can win almost a stop of highlight information too.
Blackmagic Production 4K Camera
https://www.youtube.com/user/reklama4demo
Offline

Lee Gauthier

  • Posts: 940
  • Joined: Wed Jul 16, 2014 10:51 pm

Re: DNG HIGHLIGHTS PROBLEM

PostMon Jun 20, 2016 4:28 pm

Philipp Schröppel wrote:The link is dead. Any chance to upload it again or is there a new way to deal with that problem?



Hope this helps:

https://www.sendspace.com/file/gugqb0
Offline
User avatar

Philipp Schröppel

  • Posts: 222
  • Joined: Fri Apr 25, 2014 12:41 pm
  • Location: Potsdam - Germany

Re: DNG HIGHLIGHTS PROBLEM

PostTue Jun 21, 2016 5:04 am

Lee Gauthier wrote:Hope this helps:

https://www.sendspace.com/file/gugqb0


Thank you very much, great tool!
Pete
Offline
User avatar

Philipp Schröppel

  • Posts: 222
  • Joined: Fri Apr 25, 2014 12:41 pm
  • Location: Potsdam - Germany

Re: DNG HIGHLIGHTS PROBLEM

PostThu Nov 10, 2016 4:32 pm

SlimRAW 1.7 has just been released and it supports WhiteLevel-Override!!!
http://www.slimraw.com/
Pete
Previous

Return to Cinematography

Who is online

Users browsing this forum: No registered users and 30 guests