Here’s a quick example of how Photoshop can rescue a poorly exposed image. Below is the “before” image. Move your mouse over to see the “after” shot. Some explanation after the pic.
Shooting at sunset gives some gorgeous light, but not always for everything. I could have exposed it a bit longer, and brought out more of Dani’s face, but the sky would have been blown out to the point where it was almost white. Or, I could have exposed it less, and captured the deep colors of the sky, but Dani would have been just a silhouette. I didn’t do either of those. What I did, was expose halfway between the two, giving myself a weak sky and a dark model.
Photoshop let me dodge her face and burn the sky. Those terms are holdovers from the days of printing photos on paper in a darkroom. To “dodge” was to let less light hit a spot on the paper. To burn was to let extra light hit a space. In the old days this would have taken lots of time, trying to figure out the exposures, and waving funny shaped bits of cardboard over the paper. These days it took about 3 minutes.