Have been shooting for only a few weeks now. I refuse to use flash because I don't know how. Typically with the point and shoot cameras that I've always used, the flash makes the photo look terrible. Am I wrong in assuming that you're not supposed to know if flash was used in a shot? The lighting should look natural, right?? I do not own a flash, but am thinking about picking one up. Any recommendations? I am shooting boxing and running in low light, with a Nikon D3100.