How to Photograph a Circus Show
In a Circus Show there are many factors different from any other kind of photography type. For example, the white balance does not matter too much, and you should also not worry about having too much noise: sure you will since the lighting environment is poor and the use of flash will only ruin the magic of the show.
The magic of the show is mostly based on motion and secondly on clothes. As a result, try to capture motion blur in your picture, but remember: slow shutter speed is not needed: fast motion in poor light is easy blurred at relatively fast shutter speeds. Try to capture the most expressive moments. In a show, the performers will always stop in a fixed position critical for the show, moment when they expect clapping. Be ready to shoot at this point of time.
I made these photos during the Aquatic Circus (from Italy) performance in my birth town. The main point of interest (for children more of all) were the aquatic animals. The gear I used is a Nikon D40x with Tamron 70-300mm lens. Tripod is not necessary.
The most important thing to remember when photographing a circus show is TO BE FAST. Prepare and test your gear before in such way that you will not have to change the lens or settings too often. There will be short breaks between different parts of the show, time to make some changes if needed.
Circus bring acrobats that move their body forming curves that look great in photography. Here is such a series. The difference of colors between the images is given by the lights used in the show.
Final note: remember these tips for concert photography too.