GRAPH: SHUTTER SPEED
The timeline above shows four Shutter Speed settings, 1/125, 1/60, 1/30 and 1/15. Note that they are not equal amounts of time. 1/60 is twice as long as 1/125. 1/30 is twice as long as 1/60. And, 1/15 is twice as long as 1/30. Therefore, 1/30 is only half of 1/15, 1/60 is half of 1/30, and so on.
The exposure time is longer on the right side of the graph and shorter on the left. You should be able to determine from this chart that 1/250 is half of the unit representing 1/125 and that 1/500 is half of 1/250. More importantly, the units of time moving to the left, as they are divided in half, permit less light to reach the film.
Each unit is equivalent to a Stop and can be used to adjust the amount of light reaching the film, the same as an f-stop setting on the Aperture.
The Shutter Speed and Aperture are the two major factors in making the exposure. Their relationship is relatively simple.
Graph: Shutter Speed and Aperture
HIFC FIELD GUIDE | Return to Exposure | info@houstonculture.org
Updated Oct. 2001