This video explains how to post process EXR in other applications. Applications discussed are Davinci Resolve, Natron, Darktable, Affinity Photo (paid), and Krita. Also, I show why it is a good idea to use other applications for post process and the video starts with an introduction:
I got some help from Troy Sobotka, Gez, JKierbel and Andrea Monzini on Twitter. They explained me generally the workaround.
Here is the video which is about 20 minutes. If you see something that is incorrect or you want to add some info, please leave a comment. You can leave comments here, on YouTube, or on Blender-artists.org. That will help the users of Blender getting better end results. And if you know more about Pivoted contrast, that would be awesome.
In the video I try to explain that in Blender’s compositor we are working with linear data. In contrast to other applications we can choose to operate on linear data or on display referred data. This later one is not possible in Blender. On top of that, most operations (nodes) are designed to work on display referred data instead of linear data. And therefore many nodes in Blender’s compositor are not working properly. It would be different if there was an option to plug them behind the transform view (Filmic for example).
One node that is working on linear data is the ASC CDL node (Color Balance, where you see a drop down to get to ASC CDL).