What is diffraction and how does it affect my photos?
Diffraction is an optical effect that occurs when light passes through a very small opening. Instead of producing a bright, clear image on the other side, it produces a blurry, disc shaped image. (Click here for a more detailed description of the physics behind this.) Diffraction can reduce the quality of your images when you use very small apertures. Many people think that images always get sharper as you decrease aperture size. This is true up to a point. Beyond this point, they start to get softer due to diffraction.
