How to open up an area of a photo that is underexposed?

[MarieMeyer]

How can I open up areas of a photo that are underexposed? For example, the interior of the bottom shoe and the side of the diagonal shoe? I don't need or expect dramatic transformations, but I would like to tweak them a bit.

[D Fosse · Accepted solution]

Try the Camera Raw filter Shadows slider. It usually works very well for precisely this sort of thing.

[MarieMeyer]

Oh. My. Goodness.

[MarieMeyer]

Can it be masked so that it applies only to selected areas, so I can use it more aggressively?

[Ged_Traynor]

You could convert the layer to a smart object before opening in ACR, then you can paint away where you don't want the effect applied on the smart filter layer mask

[Lumigraphics]

Just select the area you want it applied to, or create a Smart Object, or duplicate the layer and filter. You can also use Shadow/Highlight adjustment. Opening shadows can cause noise and banding problems so check your results to see if you have to deal with those.