Quote Originally Posted by nick mulder View Post
Hang on - what are you (we, possibly) attempting to compare here ?

The histogram from one digital representation of a scanned image to a digital camera originated image of what I'm assuming is another another scene ??
I think we are trying to figure out whether being an Autochrome does something special to the distribution of tones.

One thing to establish before we start thinking about that is indeed whether there is something special about that, i.e. whether histograms of representations of Autochromes indeed would/could differ from histograms of represenations of other images.
If so, there is a possibility that such a difference could (!) be due to the nature of Autochromes. If not, there's nothing to think about.