Tonal contrast actions in Photoshop give control over the contrast in the highlights, mid tones and also in the shadow areeas of images, each can be controlled for seperate adjustment.
Tonal contrast can be applied seperately to selected areas of the image or can be applied to the whole image. In the image above the tonal contrast has only been applied to the water area and in the image below the tonal contrast has been applied to the whole image.
Tonal contrast can be appled to a certain area of an image to bring attention to the centre of interest of the image.
Tonal contrast is also used to bring out texture in certain areas of the image, it can be very effective in bringing out texture in sand, water, timber and other similar features.
Tonal contrast can be applied using software from NIK. Versions are available for use as Photoshop plug-ins and also as a seperate module for Nikon Capture NX.