So the picture you took of the sunset with your $100 digital camera is under developed, I’m shocked. We’ll we need to fix it before we upload it so it doesn’t look like all the other millions of sunset photos on flickr.
We can fix it in two steps. First dupe the layer. Second set the overlying layer to Screen. If it’s too bright, reduce the opacity of the top layer; too dark, dupe yet another layer and set it to Screen.