Thought it would be an easy-peasy-1-hour-project, particle system proved me wrong.
I’ve tried to mimic dslr macro photography but I’m not sure whether onion rings would be distorted that much. This was done with lens texture in front of camera.
For this project I’ve also recreated whole optical block from an old soviet lens but it turns out that lens simulation is impossible with Cycles and my CPU is way too slow for viewport preview in LuxCore. So this one is faked.
Only two textures are used, albedo for grass and hdri environment.
Rendered with Cycles 2.93, took about 20 minutes, 2000 samples, single RTX 2070.
Post process beauty render