The Zone Mask Filter is an extremely versatile Photoshop plugin designed for both astronomical images and terrestrial photographs.  Zone Mask enhances images by selectively compressing tonal ranges (brightening shadows and returning detail to washed-out highlights), strengthening fine detail, and sharpening the image.  The user is given complete control of these functions, allowing very impressive results to be achieved with very little work.  For more details, visit the Zone Mask Filter product page and see the sample images at the link below.

Zone Mask Sample Images

This tutorial is divided into two sections, one on processing astrophotos and one on processing regular terrestrial images.

Zone Mask Tutorials