EXR Output Overexposed

Question

Saving a render as openEXR (single layer) is very overexposed compared to saving to PNG. I've viewed the .exr file in Resolve as well as other video/image editors. Everything appears brighter and with excessive contrast.

Answer 1

It's because of the different Color Management: when you render a scene in Blender, all light informations that get created for every pixel lay in a range that can go from 0 to nearly infinite, this realm is called "scene referred".

In order to be able to view the render on an ordinary monitor (that can handle only a 0.0 to 1.0 value, or 0 to 255 if you count in 8-bit format) the scene referred values are projected to the 0 - 1 zone, via some kind of "View transform": generally Filmic or AgX, with different "flavours" (medium contrast or high contrast) choosen by the artist. This transformed color management is called "View referred".

PNG saves the view referred scene, which applies also some kind of Gamma correction, in order to follow our eyes' sensibility.

EXR saves the scene referred data, in a linear fashion, without any Gamma correction and without any View transform (no Filmic, nor AgX).

PNG is better if you want to publish the image "as it is" (even if it cannot handle some transparency situations, search for glows disappearing problems related to the PNG format itself).

EXR is far better if you want to post produce the image, because it retains much more informations about the scene, and the linear format handles better all math operations which are tipically performed during Color grading and compositing.

In order to see the correct colors in DaVinci or others softwares, you have to apply to EXR a minimum of two color transforms (depending on the Color Management workflow you follow): a simple example would be a DaVinci standard LUT that you can find under VFX LUT menu, called "Linear to rec709", followed by the view transform you used in Blender (filmic or AgX).

In order to mantain the advantages of Scene referred linear EXR data, you have to apply thoose transformations at the very end of the process (and during monitoring the composite).

The setup for having automatically DaVinci recognize EXR and applying correct color transforms can be a little tricky, but it brings much more powerful and professional looking composite and Color Graded results.

In my picture I'm showing that it's possible to install all flimic and AgX View transform on Resolve (with a simple copy and paste operation in the correct folders, from Blender Color management files to DaVinci's ones), while the standard VFX - Linear to rec 709 comes with DaVinci by default.

Search for Color Management tutorials, with keywords "EXR, filmic and AgX" for more infos.