A few posts ago I talked about the value of using a twilight sky when shooting city skylines and I think you'll also find that's equally good advice when shooting carnival rides. This past weekend I went to a large country fair in Hebron, Connecticut and part of the fair, of course, was a large midway of carnival rides. I have a hard time resisting the inherent motion and color of carnival rides and so I always carve out an hour or so to shoot them regardless of how tired I am from the rest of the day's shooting.
The lights on the rides started coming on just as the sun began to set but unfortunately the lights on the Ferris wheel weren't as exciting as some others that I've photographed. As the daylight disappeared and the sky took on a rich sapphire blue, however, the contrast between the artificial lights and the sky got very intense. This beautiful contrast only lasted about 15-20 minutes and then the magic was gone. At one point, however, the twilight reached a peak of brilliance and there was an almost even balance in luminosity between the ride and the sky and that's when the shots really started to pop. I kept on shooting after the sky had faded to gray and then black, but I knew that the best photos were shot right at that height of the twilight.
If you're going out to shoot a carnival soon, scout out your shots during the last hour of daylight and be ready to shoot as the sun sets and the sky illuminates with that glowing blue color. You might even get some good shots with the last rays of daylight illuminating the rides as the sky grows darker. In this case I was actually facing right into the area of sky where the sun had set (look down low and you can even see a small glimmer of the sunset), but that was just dictated by that particular locale. I probably could have shot with the sun behind me, but this was the viewpoint that worked the best overall.
Incidentally, this is one of the rare times that I didn't use a tripod, largely because the fair was so crowded I was afraid someone would trip on it. But by using a fence rail from a nearby ride, I was able to handhold this shot at 1/8 second (with an 18-70mm Nikkor zoom); it's not the sharpest shot I've ever made but it is sharp enough. I even managed to do some motion shots hand held, though the inherent movement of the rides turned the shots into abstracts so sharpness wasn't a concern.