We stopped out in the desert on our way home from California to Arizona where we can be close to the railroad tracks. I turned the polarizing filter way up after noticing the nice puffy clouds. If you take the time to look along the tracks you can find round glass balls that are the size of a quarter. To haul glass they would make the marbles for easy loading and unloading. They would bounce out of the railroad cars for us to find lol.. Oh I love the thrill of standing this close to the train as it goes by at around 50mph.