Heres and interesting way to “turn on the lights” in the city when its still too early for them to come on. Take two photos. The first image you capture earlier as the sun sets to get the pretty color in the sky. When you do this it is very likely that the city lights haven’t all come on yet, so you get a nice sky and visible foreground, but no lights. Leave your camera alone on the tripod for 20-30 minutes and allow the scene to get darker and the lights in the city to come on, then take another picture of those lights. Now you have a great shot of the lights, but you’ve lost the color in the sky. Now bring both pictures into Photoshop as layers. It doesn’t really matter which picture is the top layer, either the darker of lighter one. Change the “Blend mode” of the top picture to “Lighten”…Bang! The lights come on in the city. Now you have a nice sky AND city lights, and everything is right with the world again.
(click the images to enlarge)