Local Contrast
Contrast measured between neighbouring areas rather than across the whole tonal range, which strongly affects perceived depth and clarity.
Measured in
%
In depth
Global contrast changes the relationship between the darkest and lightest tones; local contrast changes the relationship between adjacent regions of similar brightness. Because the eye judges form largely from local differences, raising it makes an image look more three-dimensional without any change to its endpoints.
Examples in practice
Raising local contrast on a mountain range separates each ridge from the next without darkening the shadows at all.