We all know that decreasing the aperture (bigger f nunber) increases the depth of field in our pictures. But do we all really understand that at some stage the smaller we make the aperture in our lens the softer the image becomes? This is due to an optical phenomenon know as difraction. The above video does a great job of explaining this in a way that is very easy to understand. Knowing your camera is more about knowing all the buttons. Its also about knowing where that sweet spot is!