The amazingly smooth shadows of D7k raw files
There has been some noise (oops) around here and in other internet forums about the pattern noise (straight banding) that one gets from trying to recover extreme shadows from D5200 raw files. Here is the RAW analysis of one such example (check images at original size):
So I went back to a DR test I did in late 2011 with my D7k and checked the files again. Here is one such file opened in ACR:
To see the DR of this scene, here's the RAW histogram:
As one can see, it goes above 14.5 EV (I recall I had measured it at about 16EV with the in-camera spotmeter). You can also see that there are not clipped HL, but some blacks in channels.
Now here is the same scene applying +4exp comp and 100 recovery in ACR:
Detail of the top right area at 100% (see it at original size):
One may try to find some linear banding (horizontal), but the scene is about clean.
Now here is the same area with the points where the values of the 3 channels are at or below 2 highlighted (you need to see it at original size to appreciate it).
Observe how smooth this scene is. It is at this point that the D5200 showed problems, the horizontal pattern was clearly visible there. The box is to check the typical values in this area, they are registered in the box in the middle of the top bar. Max values are in the 10-13 range and averages ae quite low. If there's any banding in the converted and recovered fie, it's not a problem with the file, but with the conversion produced by ACR.