Shutter Basics
Preface: Shutter is often confused with exposure, Exposure is a combination of all the cameras adjustments to make an image, shutter deals specifically with time, sometimes referred to as "exposure time" which can be confusing for beginning photographers. It is important to make the distinction between the two in order to learn all the concepts of exposure individually.
The shutter is a curtain in the back of the camera that opens and closes to expose your sensor of film to light. By speeding up and slowing down this action it allows you to change the brightness of the image. These adjustments are measured in seconds and fractions of a second with stops at each multiple of two. This speed can be anywhere from hours long to 1/8000 of a second on some cameras. The sequence we'll be looking at is:
2sec 1sec 1/2 1/4 1/8 1/15 1/30 1/60 1/125 1/250 1/500 1/1000 1/2000
Two seconds is the longest shutter speed in the sequence and 1/2000 is the fastest shutter speed in this sequence. With each stop in the sequence starting with 2 seconds, you are cutting the time in half, and therefore cutting the amount of light in half. Or making it one stop darker. 1 second is half as bright as 2 sec and 1/2 is half as bright as 1sec. This works in the opposite direction as well. 1/1000th is twice as bright as 1/2000th, and 1/500th is twice as bright as 1/1000th. This allows you to make dark areas bright or bright areas dark.
Because shutter speed deals with time, the passage of time appears with each shutter speed. The image is exposed for as long as the shutter is open so anything moving during that time will appear to move causing motion blur. As you speed up the shutter the effect becomes less and less noticeable. This can however be used to great effect in your images as a way to express creative vision through motion.
Example of motion blur at 1/125th
20 second exposure allows you to capture stars.
I am a photographer and content creator from the Bay Area of California.
