f stops are also called aperture settings. Actually the smaller the number on the scale the larger the opening of the aperture. Why you ask? You didn't ask? Well hell I'm gonna tell you anyway. The number are actually the demoniator of fractions. Yep f2.8 is acutally 1/2.8 or almost all of the total opening size in play. f16 is actually 1/16 or a much smaller part of the total in play. Think of it this way would you rather have 1/16 of a million dollars or 1/2.8 of a million dollars. See now isnt that simple. There are some formulas to figure how the number are derived but I never bothered to learn them. Remember the faucet... well it is going to come into play again. Just remember the smaller the number on the scale (or the larger the fraction) the higher the volume of light.