Online Tutorials: Shutter Speed
Shutter speed is a measure of how long the shutter remains open when the picture is taken. A set of thin, lightweight shutters that normally block the light from the media is moved away temporarily to allow the correct exposure to be made.
A precise shutter speed is not always required and it can be quite creative to show a little motion blur representing speed and movement in your photography. If you are changing your shutter speed, you will also need to make adjustments to your aperture and your ISO settings to achieve your desired results.
Shutter speeds are calibrated to be twice as fast (or 1 stop faster) than the previous setting and twice as slow (or 1 stop slower) than the next setting.
e.g.1/250s is twice as fast as the previous setting 1/125s but is twice as slow as the next setting 1/500s.
Most modern cameras with the ability to change the shutter speed have a dial to make these adjustments. This dial will click when it is turned; each time it clicks, it changes the settings by 1/3 of a stop (three clicks for a full "stop").
1/20 Second F32
1/1000 Second F3.5
As you can see from the two examples there is a large difference in the shutter speed with two aperture sizes that are at relative opposite ends of the range. You should clearly see the effects of depth of field from these two aperture settings.
There is often an extra setting on the camera's shutter speed dial called the Bulb or 'B' setting. This allows the shutter to remain open for as long as the release button is held down. This is very useful for night shots or shots which are in near total darkness and require a very long shutter speed to allow correct exposure. If you choose to use this setting you need to have considered the factors listed in the night photography section.