I’m lost
Could you give me a nice preset for animation architectural viz with foliage
thx
So did you figure it out? What was your problem after all? 
Pass limit : 30
GI Primary and Secondary : Path tracing for both (instead Path tracing and UHD)
Sampling Balance GI/AA : 32 (instead 16)
I’ve tried a bunch of settings last week and this one is good but very long. We can surely speed up the render by decreasing some settings but I’m not a specialist.
First, GI/AA = is wrong. Better 16 or, maybe, 6, because you have a lot of details.
Second, there isn’t any special setting in corona. If 30 passes aren’t enough, you have to wait more =)
You can lower MSI to 5 and Rays bounces from 25 to 10.
About GI/AA :
https://coronarenderer.freshdesk.com/support/solutions/articles/5000526159-what-is-gi-vs-aa-balance-
16 by default are samples for GI. More you get, better is GI.
2 by default are a multiplier for direct light.
By default, this is 16x2 = 32 samples
If you get 32/4 :
- 32 samples for GI
- 32x4 samples for direct light