There are three ways to control the amount of light that enters your camera: aperture, shutter speed, and ISO. Each of these controls is very important and functions both separately and in conjunction with the others. The art is in learning to balance all three so that you are rewarded with a perfectly exposed photograph.
Let us talk about Shutter Speeds. We refer to shutter speeds in measurements of 1/x. With the advances in camera technology today the range of shutter speeds have grown. However, for our purpose of general understanding we will focus on the range from 30 seconds to 1/1000 of a second.
First, what is a shutter speed?
Shutter speed refers to how long the aperture is open. This directly affects the amount of light let into the camera.
What does this mean?
Seems simple enough – but the control of how long light is let into the camera greatly affects a photograph.
The most pointed of the effects of shutter speed on a photograph is that the shutter speed controls how movement is captured.
What does this mean?
A photograph with a slow shutter speed allows the motion to blur across the photograph.
A fast shutter speed on the other hand, freezes all movement in that moment. Often photographers use a fast shutter speed in sports photography so that all motion is brought to a complete standstill in the image.
Controlling Movement with Shutter Speed
Shutter Speed 1/1000 freezes all human movement – hummingbird wings and flying bullets require faster speeds.
Shutter Speed 30 captures all movement that occurs in those 30 seconds, so the moving object becomes blurry.
It is a gradual range from one extreme to the other. I highly recommend learning your camera’s shutter speeds by heart so that when you want to capture movement in your photographs, you automatically know exactly which shutter speed to use.
The amount of light you let into the camera (by changing how long you leave the hole open) directly affects how large of an aperture you will need. It is very important to keep these two controls in balance to achieve the correct exposure for your photograph.