“Photoshop and Elements allow for layer blend modes that change the way layers react with each other. Some of them you will use in every day work. If you have a photo that is too dark, for example, many times a quick fix is to duplicate the photo layer in the layers palette and change the duplicate layer mode to Screen. If a photo is too light it can sometimes be corrected by duplicating the photo layer and changing the layer mode to Multiply. ”
Photoshop Blending modes at Northlight
