Shutter Speed
Shutter speed affects photographs paired with aperture to affect how much light a camera absorbs in a certain amount of time. The more time you allow the lens to absorb and process light, the more light goes into the final image
In this post Lyndzee Ellsworth (see their blog at epblog.net) shares some images from a shoot to show what impact shutter speed can have on images.
Starting with the first photo, I set the shutter speed for a 15 sec exposure (which on your camera should look like 15”). With the shutter open for 15 seconds, all of the light that the lens can capture in that 15 seconds is recorded and processed. By the photo below you can tell that 15 seconds was too much, so I changed it to 10, then 8 and then finally landed on 5 seconds to achieve what in my eye was the best shot.
Shutter speed can be utilized to capture moving subjects more easily.
The same rule can be used to get the opposite effect. If the shutter speed is set slow, photos can either blur or drag light for the desired effect.