One of the hardest concepts for beginners is understanding light and how it behaves. As I've said many times before, we can not see light, just the effect of light. Once you start thinking of light in terms of particles of energy then it starts becoming easier to understand. Specially since light behaves in very predictable ways. This article discusses angle of incidence . A fundamental concept that appears in many areas of photography. Getting a grasp of this concept will open up a whole new realm of possibilities for you as you move forward in your career or hobby. An incidence  is simply an  occurrence , an action that takes place at a specific point. In our case this incidence is the point at which a particle of light strikes a surface. The law of physics states that whenever an object strikes another object there will be an equal but opposite reaction. Because we are talking about a particle of light, when that particle hits a surface it deflects off that ...