Saving in EXR the 2.2 correction is automatically applied, right? so if i want to save in 1.8 i think we have to compensate this and put in Preferences > Output = 0.818 , this way 2.2 x 0.818 = 1.8 (leaving Color mapping to 1), is this right?
Saving LDRI no problems since we can put 1.8 directly in Preferences > Output (or leaving this to 1 an Saving Override to 1.8 or…using Color mapping).
All this issue comes from a Master Class i was recently in by a international famous cg artist where he explained very fast and not (for me) so clear… (I asked for the EXR output at 1.8 an he told me leaving Display to 1.8 was enough…not Color mapping nor Save override…)
EXR’s will automatically correct to a 2.2 gamma. So to work with a 1.8 gamma, you simply need to set your out put gamma so that is proportional to 2.2. Meaning you should set your output gamma to to 0.818 instead of 1.0.
btw this thread was the base of what i wrote below
I made some test and all seems to work fine, comparing EXR vs JPG i only noticed some little changes in shadow areas, these are darker in the EXR than the JPG (saved with Override at 1.8 ).
I usually leave them set to a 2.2 gamma since that is what they were developed with in Photoshop. I am not sure there is a hard fast rule other than to do what you feel looks good.