Nikon D90 Manual page 14

14 The Camera
1/200 of a second.
As this duck was swimming toward me I needed a fast enough shutter speed to stop its motion. The duck was not
moving extremely quickly so 1/200 of a second was fast enough to keep it from blurring.
1/25 of a second.
In this photograph of reflections in a river, a slower shutter speed renders a combination of areas that are smooth
and others that are distinct.