Samsung Galaxy NX500 Camera User Manual (en)

Concepts in Photography
Shutter speed
Shutter speed refers to the amount of time it takes to open and close the 
shutter. It controls the amount of light which passes through the aperture 
before it reaches the image sensor.
Shutter speeds are measured in seconds and parts of a second. On 
many cameras, the shutter speeds are approximately halved with each 
succeeding setting - 1 s, 1/2 s, 1/4 s, 1/8 s, 1/15 s, etc. Like successive 
aperture settings, each successive shutter speed setting lets in about half 
the amount of light. Consequently, each successive shutter speed setting 
equals an EV (Exposure Value) change of about 1 EV.
+1 EV
-1 EV
1 s
1/2 s
1/4 s
1/8 s
1/15 s
1/30 s
Shutter speed
Therefore, the faster the shutter speed, the less light will be let in. Likewise, 
the slower the shutter speed, the more light will be let in.
A slow shutter speed allows more light into the camera, making photos 
brighter. However, because the shutter is open longer, moving subjects 
appear blurred. A fast shutter speed allows less light in, making photos 
darker. However, because the shutter is open for a shorter time, moving 
subjects look sharper and more focused.
1 s
1/250 s