Shadow recovery for photo restoration
In photo restoration you find that more often than not you will be recovering shadows. Photoshop has a tool called shadows/highlights. This tool enables you to slide two sliders to change the way the shadows and highlights are affected. In simple term the shadow slider reveals details in the shadows and the highlight slider reveals details in the highlights. What is important to note though is that they are only revealed if they are there in the first place. This will not magically create details that are not buried there in the first place.
This tool can be used in conjunction with the recovering highlights to squeeze a bit more texture and tone into the image.