What Diffraction Actually Is, and Why Photographers Worry About f/16

A 24mm lens at f/8 has an opening 3.00 mm across. A 600mm lens at f/8 has one 75 mm across, 25 times wider, and it draws a diffraction pattern on the sky 25 times finer. Both land a blur spot on your sensor exactly 10.7 microns wide. Every other limit in photography has a price attached. Aberrations yield to better glass, noise yields to a bigger sensor, flare yields to better coatings. Diffraction yields to nothing, because it is not a property of your lens at all.[Read More]