Originally posted by MJKoski Just open ETTR exposed cRAW with RAWDigger and check the histogram. It is has gaps in the hightlight-end. Now, one pulls back the exposure with the gaps and gets stairstepping gradients where there should be smooth tonal transitions.
No, it is not an issue in all files. Just those that should contain smooth skies for example. Or other large flat surfaces.
I do not doubt what you are saying at all. I do not have access to any cRAW images (unless that is the standard Sony output!). Just a quick look at a raw file from a Sony AR7 II. Seems to confirm a lot:
The Sony AR7 II file I look at in RD is certainly not what I would have expected to see from a 14 bit capture. Showing a Max value RGBG2 = 3546. A 14 bit capture you would expect to see values around 16384.
Seems to confirm that it is close enough to an 11 bit capture which would equal values of 2048 with the +7 bit that Sony state making up the rest.
The histogram shows it hitting the wall for the Green channels at around +2.5EV. The red appears about -1/2EV below that.
So applying ETTR as it was meant to be used at base ISO (and scene dynamic range that sat inside your cameras DR) if you metered an important highlight area you could apply a max exposure correction of +2EV - +2.5EV. Theoretically not clipping highlights.
But the problem remains in how the manufacturer decides to bin data and the most obvious place is in the highlight region as the first stop of exposure contains half of the data. So bin some of that and a user is left with the potential problem of editing and pushing the data too much causing misery