Snowmelt above Flagstaff, Arizona creates the spectacular Chocolate Falls. This seasonal cascade offered me the perfect venue for a lesson in the effects of longer shutter speeds on moving water. Photo by Bruce Dorn. Canon EOS 5D Mark IV, Canon EF 24-70mm f/2.8L II USM at 24mm, Tiffen ND 0.6 filter. Exposure: 5 sec., ƒ/10, ISO 100. Remember when photography was a fresh and hot-blooded passion? I do. I hooked up with my first camera during the Summer of Love, 1969, and was immediately and hopelessly hooked. Everything was new and exciting and I had eyes for nothing else. I studied magazine articles offering technical advice and “Top 10 Tips,” but I also had the benefit of learning in person from...