faucet

faucet
Originally uploaded by Michael Slear

Someone asked, what’s an f stop? Technically, its the f-number or focal ratio of an optical system that expresses the diameter of the entrance pupil in terms of the effective focal length of the lens....Whew! Simply its the size of the hole or aperture which can be adjusted and hence vary the amount of light passing thru the lens to reach the film or light sensor. (Just like your pupil.) Think of it like a faucet, if you want to fill a quart jug with water, a garden hose may take a few seconds, switch to a fire hose and jug will fill in a split second. As u try smaller and smaller hoses the time it takes to fill gets progressively longer. Any equivalent combination of time and size of hose produces the ‘correct’ result: a full quart jug or in photography a correct exposure. This shot was one of those confluences, red handle, blue sky, just turn it on, slow shutter to show water movement and slight diagonal to emphasize motion. Note also main subject at intersection of the tic tac toe.