I recently bought an ND filter, and I thought the Wonder Wheel might make an interesting long exposure. I put my camera on a tripod, set up the composition, and then put on the ND filter. I set the aperture to f20 and put my camera in bulb mode. Once the Wonder Wheel started to spin, I opened the shutter using a remote control. I left the shutter open for 25 seconds. That was enough to capture the movement of the wheel and create some interesting and colorful circles.