Color Management – Tone Mapping: AgX versus ACES 1.2/1.3
For detailed information about this research please read the description below this video:
• Color Management – Tone Mapping: AgX versu...
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Additional information:
Blender 3.5 Beta scene with a plane and a sphere using a standard white (0.8) PBR material. The plane's roughness is set to 1.0. The sphere's roughness is set to 0.0. The area light is set to a high value of 1,000 watts. The light color is animated through the whole HUE spectrum.
The top left sequence was rendered in Blender in Linear Rec.709 I-D65 color space and tone mapped with AgX to sRGB color space. The other sequences were rendered in Blender in ACEScg color space and tone mapped with ACES 1.2 and ACES 1.3 to sRGB color space. It was claimed that ACES 1.3 has fixed a color clipping. But this color clipping still happens.
The top right sequence is an experiment with setting the input color space of the ACEScg EXR sequence to Linear Rec.709 (sRGB). This removes the color clipping by reducing the wide #gamut of ACEScg to the smaller gamut of Linear Rec.709 (sRGB).
However, the AgX tone mapped result is 100% robust and close to how a classic ARRI film camera would record and display color and light intensity. More light (overexposure) will cause a natural desaturation of colors. The ACEScg input set to Linear Rec.709 (sRGB) tone mapped with ACES 1.3 to sRGB is more saturated and has issues when the light color changes to magenta.
Conclusion: The ACES tone mapping protocol fails to transform ACEScg properly. The AgX tone mapping result feels more natural from a relative perception.