Eperimenting with a wide angle (12-24mm Sigma) at night trying to catch the lights. The small carnival didn't have a lot of lights running. I got the impression that they were either out of repair or conserving energy. It took me a while to realize I would get better results by lengthening the shutter speed. Most shutter speeds are 1/5 second to 0.5 seconds.
A photographer was shooting our orchestra rehearsal and liked the patina of my tuba. I realized I had a bunch of old instruments and a nice looking guitar as well. I dug out my gear and shot using available light through a diffuser in the window.