HI 
Thanks for your suggestion, I’ll try that ASAP.
That being said, the problem reminds me of the old days when it was sometimes tricky to use linear workflow, when we got double gamma correction applied on the output renderings (3dsmax, VRay …)
With the images I rendered through MRQ, applying a gamma compensation curve in post ends with the original look, the one as seen in the editor viewport … anyway, be sure I’ll try your fog suggestion next week.
Thank you for your help.
Regards.