At the San Francisco Cable Car Museum and Power Station. These wheels turn all the time the cable cars are running. I did not have my tripod with me but I definitely wanted to use a slow shutter speed to create blur and show the wheels in motion. So I had to find something solid to brace the camera against. Found a suitable railing. It took a few tries playing with shutter speed to get what I thought was the right amount of blur while keeping everything else sharp, but I felt I nailed it. They say an artist is successful if they accomplish what they set out to do. This day I was satisfied.