I was shooting with a 50mm normal lens inside a gym under florescent lights. I moved forward and backward along the sidelines to frame the teen working with younger judo students or sparring with this classmates. With his dark skin, if I shot him in front of the blue padding that lined the gym’s walls, he tended to disappear. I had to keep moving to keep the background behind him light so that he stood out.
Once I established the limitations of the assignment -- the lighting, noisy backgrounds, the focal length of my lens, the speed of the action in front of me, etc. -- I found I was free to do whatever I wanted. Identifying and solving an assignment’s technical challenges up front means I can shoot however I want as I go. It’s easier to make adjustments while shooting than to try to fix problems later while processing the images.