shutter speed controls time
more precisely
it controls how long the camera records light
that single variable has a powerful effect
it determines how motion appears in the photograph
freezing time
a fast shutter speed captures a very short slice of time
1/1000 of a second
1/2000
even faster
at these speeds motion is frozen
a bird mid flight
a splash of water
a person caught between steps
everything appears sharp
defined
still
stretching time
a slow shutter speed does the opposite
it records a longer slice of time
1/30 of a second
1/10
1 second or more
now movement becomes visible
not as a moment
but as a trace
cars become light trails
water becomes smooth
people blur as they pass through the frame
what this means
shutter speed is not just a setting
it is a decision
do you want to freeze motion
or show it
neither is correct
both are valid
it depends on what you want the photograph to say
the trade off
there is always a trade off
faster shutter speeds let in less light
slower shutter speeds let in more
every change here affects exposure
this is where the relationship with aperture begins
seeing motion
before you touch the camera
look at the scene
ask yourself
is anything moving
how fast
and how do you want it to appear
sharp
blurred
or somewhere in between
the answer determines your shutter speed
next: aperture and depth of field explained
previous: why there are no perfect camera settings