A primary creative variable: how long the shutter stays open. Fast freezes action, slow blurs action. This topic is iffy with many point-and-shoots, where you can't choose your shutter speed.
Water is transformed by both slow AND fast exposure speeds.
The catch is that you CAN'T just choose your shutter speed without adjusting aperture, ISO, or light level to get a good exposure. In this sequence we shot at f22 in order to get both the water and Nicole in focus. The only way to vary the exposure was by adjusting the ISO and by adding neutral density filters.
Remember: the blurring of the water depends on how fast the water is moving — these exposure times are only meaningful at our little waterfall. The point here is to think about playing with exposure time, not to suggest there is a "correct" shutter speed for any effect.
Bottom Line: Exposure time is a critical creative option, which often takes extra work to master.
Left
Right
Fast shutter: water almost frozen in motion
1/750, f22, 100mm, ISO 6400
I would have liked to have used an even faster shutter speed, like 1/4000, because water looks different the faster the exposure but I wanted the f22 setting for depth of field.
At 250th the the water is already stating to blur.
1/250, f22, 100mm, ISO 3200
At 125th the water is blurry, but does not get to a pleasing blur until you slow down close to a full second.
1/125, f22, 100mm, ISO 1600
At a 60th you see some bright streaks, like the one just to the right of Nicole's cheek. The highlights on the water can creates some nice effects at medium speeds.
1/60, f22, 100mm, ISO 800
At a 20th things are iffy — neither sharp nor blurry enough to be pleasing or interesting.
1/20, f22, 100mm, ISO 400
At a 10th the smoothing effect is starting to happen.
1/10, f22, 100mm, ISO 200
At a 1/6th the smoothing effect is not bad.
1/6, f22, 100mm, ISO 100
At a 1/2 the smoothing effect on the water is interesting, but Nicole is blurry because she moved — you try sitting perfect still in a waterfall.
I would have like to go all the way to a full second, for an even smoother water look, but Nicole was getting way too blurry.
1/2, f22, 100mm, ISO 100 + neutral density filter
Fast shutter: water almost frozen in motion
1/750, f22, 100mm, ISO 6400
I would have liked to have used an even faster shutter speed, like 1/4000, because water looks different the faster the exposure but I wanted the f22 setting for depth of field.
At 250th the the water is already stating to blur.
1/250, f22, 100mm, ISO 3200
At 125th the water is blurry, but does not get to a pleasing blur until you slow down close to a full second.
1/125, f22, 100mm, ISO 1600
At a 60th you see some bright streaks, like the one just to the right of Nicole's cheek. The highlights on the water can creates some nice effects at medium speeds.
1/60, f22, 100mm, ISO 800
At a 20th things are iffy — neither sharp nor blurry enough to be pleasing or interesting.
1/20, f22, 100mm, ISO 400
At a 10th the smoothing effect is starting to happen.
1/10, f22, 100mm, ISO 200
At a 1/6th the smoothing effect is not bad.
1/6, f22, 100mm, ISO 100
At a 1/2 the smoothing effect on the water is interesting, but Nicole is blurry because she moved — you try sitting perfect still in a waterfall.
I would have like to go all the way to a full second, for an even smoother water look, but Nicole was getting way too blurry.
