Applying "Adjust Levels, even using "Auto", corresponds to the traditional darkroom task of finding the proper paper grade or variable contrast filter setting to properly include both low and high values.

No black
Full tonal range, blocked low values
Somewhat more difficult is the traditional process of finding a paper which has the proper "response curve", long or short toe, etc.. Adjusting the shape of the response curve is done by the manufacturer by changing the formulation of the paper emulsion. The photographer has very little control over this characteristic and must experiment with different paper / developer combinations. A similar result is accomplished here with Photoshop. and the "Adjust Curve" tool, or the "slider" control of the "Adjust Levels" tool.
Increased low value separation.

RETURN HOME