I dont care if the stops of DR are 12 or 15. I just want to know, why I can recover highlights that were marked as "blown" in the histogram?
So I should expose "ETTR" and magically assume, that the histogram is wider than it seems and can go 2 more stops to the right
Maybe it is a hardware limitation, because the histogram reads from the display, not the sensor data. Not sure how that goes...
About the test - yes the Prores was in "film".
The test is fairly simple. Just point the camera to a bright scene, which is clearly over-exposed. ISO 800, as in "native". Then I make 1 shot in RAW (film), then I make the same shot in Prores 422 (film).
Then in Premiere, I use the "lumetri color" effect. With the RAW shot, I can recover 2-3 stops. With the Prores shot, I can recover about 0.5 stops.
Well maybe it is a Premiere drawback, I should repeat the test with Davinci.