Lightening A Photo

I took this picture last week at a pumpkin farm in northern Indiana. In the photo is my daughter's first grade class. The photo was taken inside the barn without flash, so it was very dark. I used Adobe Photoshop to lighten the photo. I used the Brightness/Contrast feature and I brightened the picture and lightened the contrast. The first picture is the photoshopped one, with the original second.