I've seen this mentioned a few times but not sure there's been a quick example posted or feedback from the devs.
Render this scene using the IR, then do the same doing a final render and the brightness is changed.
Full-speed non-debug version
Build timestamp: Oct 24 2017 16:56:46
Version: B1 daily Oct 24 2017 (core 1.7 RC10)
Cinema version: CINEMA 4D Studio R19.024 S
Plugin status: initialized successfully
Cheers