Photography Tips and Tricks - 41 (Shutter Speed Rule for Focal Length)

There is a rule for shutter speed and focal length.  This works for static or slow-moving objects.  The rule is to have a shutter speed equal to 1/focal length.  So, a 200 mm focal length should be 1/200 or faster.  This is to compensate for the camera shake.  If you have a fast-moving subject try doubling or tripling the shutter speed.