Ok, kinda big update. I've improved the CoronaCameraMod to include all the basic photographic settings:
The same controls are in render settings, CameraMod overrides them on per-camera basis. You can instance the mod to multiple cameras, even use it with other render plugins cameras.
Next I've added physical units to CoronaLight: candela, lux, lumen, and default ones, which are now interpreted as watts per steradian per square meter. CoronaSun/Sky will remain the way it is, giving physically correct intensity (achieved when its intensity multiplier is set to 1).
All radiance units (standard lights, emission mtl) are assumed to be in watts per steradian per square meter.
PS: clipping values are now taken from the camera