something was different - see statistics across the frame in this 2058 NEF
and skin area =
and in 2059 NEF
and skin area =
sensor saturation did not change for skin area, but something else ( ambient light, framing of the area around the face, etc ) did change so some other areas in the sensor outside of the skin area in question got more saturated and that presented a problem for DxO code
so in 2059 DxO code calculates apparently data as clipped and in 2058 as not ( because it thinks that it is way down below clipping point - which of course it is , but in BOTH raw files )… as usual - somebody in DxO either has a math difficulties or was not aware how and where to get clipping level for raw files
so this where the bug probably lies more precisely , it is even worse it seems : (A) DxO code can’t decide where actual clipping point is and then (B) still clips the UNCLIPPED data that lies close to ( properly or incorrectly calculated ) clipping point
even you convert NEF to DNG using Adobe DNG Converter and kind Adobe engineers calculate that for DxO ( while level tag :: 0xc61d WhiteLevel = 15892 ), DxO still ignores that and calculates clipping incorrectly and then ( icing on the cake ) still clips unclipped data close to incorrectly calculated clipping point …
in 2058 NEF skin area lies ~0.8 stop below clipping if DxO calculates clipping point based on the max DN found in the frame
in 2059 NEF skin area lies ( it is NOT, but we about DxO point of view ) ~0.3 stop below clipping if DxO calculates ( incorrectly ) clipping point based on the max DN found in the frame
so for 2059 NEF DxO decides to clip unclipped data because it calculates white point incorrectly and then does the bad thing and for 2058 NEF it does not because god bless something that saturated the sensor further somewhere else in the frame
PS: that something for in 2058 NEF was the front/light/window facing side of the box… it is fully saturated in greens and almost in blue channels in the frame , so gives imperfect DxO code a hint where white level is
