It was a chilling 90 degrees that day in the City. Kidding. At the Polo Field In Golden Gate Park baking in the hot sunny day I rode the Polo Field Track for a few minutes on my single speed and decided to start capturing people moving fast. This gentlemen was steadily grinding on his big rig for 10 laps. He knew I was taking photos of him but didn't seem to care so I pressed on and honed in my panning technique.