I am a great fan of the Zone System. I used it when I was processing and printing Black and White film for a number of years.
Digital cameras are getting better, but cannot match the dynamic rage of film, yet.
With film you exposed for the shadows and developed the highlights and yes I know it is not as simple as that. I spent many weeks calibrating camera to film and film to paper and reading Ansel Adams books.
For digital it's the other way round, expose for the highlights and develop the shadows.
There is no process that can match the dynamic range of the human eye. This is why Ansel Adams and Fred Archer developed the Zone System as a reliable method of giving the greatest possible dynamic range in an image.
The Zone system is applicable now as it was in Ansel Adams and Fred Archers day.
A change to the curves dialog to manipulate the zones would be the easiest way. At the moment you don't have values for the tonal range, It would be ideal to be able to select for Zone System and display the Zone System values on the X,Y axis.
Must have option - No
Ideal - Yes
At the moment I will continue guess values to assist in developing the image.
