This was shot on a Sony FS7. I tracked the shot with PFTrack and added the flowers, grass, and stones in Maya. The models were converted to Arnold Scene Source (.ass) archives and then instanced hundreds of times. I shot 7 exposures of a chrome ball while on set and combined their exposures into a 32 bit EXR HDR image in Photoshop. That light probe plus a directional light were the only sources used to light the CG scene.
I did a spherical transform in Nuke from a mirroball to a latlong. I realized later this step isn’t necessarily required with Arnold’s skydome light as the light can read in a mirrorball properly.
Tracking, Light Probe, Placement