Originally posted by ozzi-paul mages were shot in RAW (dng) & converted to jpeg with ACR & default settings
The free Histogrammer program (
GUILLERMO LUIJK**-**b i t s & f o t o g r a f í a) may help. It does not decode raw files, but you can do a flat dcraw convert first to feed it a TIF or JPEG. Due to the gamma 2.2 encoding in the sRGB tone curve in the TIF, there can be more than 8 stops of DR.
Here's an 8-bit TIF I had lying around from a K20D raw conversion in SilkyPix Pro. Probably for this, a 16-bit TIF would be better.
I then used the Zones button to export R, G, B & L zonal maps. Here is the Luminance 11-zone map:
Dan.