Thought this might be interesting.

I borrowed a friends Sony FS7 on the weekend and wondered how my LS300 compared in terms of sensitivity. I set both cameras to Rec. 709 gamma, knee at 100ire, zebras at 100ire. I framed both cameras on a DSC chart and adjusted the iris until the zebras were triggered by the white chips on the chart. The LS300 was at f5.6 with the gain set to ISO 400. The FS7 was between f5.6 -f5.0 with the gain at 0db.

My light meter confirmed that at iso 400, my LS300 should be at f5.6...interesting that the FS7 was also rating at iso 400(approx.)

Just a little real world comparison.

Which lenses? Worth trying with a single t-stop calibrated lens for a proper test...

The LS300 had a Canon 50mm f1.4 with a normal Metabones smart adaptor, the FS7 had the kit zoom lens(28-135?). I realize it's not the best or most accurate way to compare, but I was expecting the Sony to be about 2 stops faster than the 300.