On this video tutorial Aaron Nace from Phlearn demonstrates how to fix dark shadows in images using Adobe Photoshop.
Shadows which block the details from your image can be a problem and learning how to get around this issue is important to almost any photographer. You can use the shadows slider in Camera RAW but the results can be a bit too much and Nace has a different method inside Photoshop itself.
Nace starts with an adjustment layer and choose levels and moves the mid point slider to the left. Now you can see more details. The problem is that you get a washed out image. Playing with the dark levels or bright levels doesn’t really help. The same problem happens if you do the same thing with curves.
A better technique that will not effect the rest of the image is opening a new duplicate layer (ctrl J) going to image>adjustment>shadows/highlights and click on show more options. Now start playing with the amount of shadows, tone and radius (don’t go too far). As you can see the highlights are not effected (unless you want to). If you need you can add some color to the shadow area with the adjustments. Super simple and very useful.