48 From the ‘Filter’ drop down menu, select ‘High Pass’ :
Drag the slider that appears to suit your image, noting that a higher value creates a more drastic, not necessarily better effect. Having clicked on the actual image to select what shows in the smaller ‘preview’ box (below) on the right hand side, I feel that a setting on the ‘Radius’ slider of 33 gives a good increase in shadowing and high point detail. This only affects the selected ‘Layer 1’ as that is the one we have selected hence the reason we can apply a shading filter.