Part of the mystic of photography is the ability to manipulate time. Photographs can become time machines, a glimpse of the past here in the present, to be sent on to the future.
Photography can stop time cold and allow us to see things that happen in milliseconds, things undetectable by our own vision equipment. Such as the photographs of Harold Edgerton such as Bullet Piercing an Apple, 1964.
Or the motion studies of Eadweard Muybridge, which slowed down time into a sequence of steps to be studies more closing that could ever be with the human eye.
Photographers have may tools at their disposal for capturing motion and time in a variety of effects. Fast shutter speeds and strobes can freeze action cold. Slow shutter speeds can imprint a multitude of time on to a single image. Take the flowing photograph of mine into consideration. The slow shutter speed image of people walking on a beach allows the figures to blur across their motion, adding a since of time to the image.
This effect can be taken to the extreme with motions blurs that become more abstract art. Here in this motion blur image taken in a tulip garden, time reduces the flowers to pure abstract colors. The meaning perhaps is lost in favor of a perhaps feeling or mood.
Camera settings to capture motion blur are not as simple as using a “slower than recommended handheld shutter speed”. The motion blur depends on the speed of the subject. Consider the bullet shot through the apple. A bullet traveling at 896 m/s is going to show blur in just about any conditions unless you have specialized equipment. Consider the movement of the people on the beach – slower by magnitudes and as such the blur can be created with perhaps a 30th of a second.
Motion blurs need to be conducted with thought and purpose. Just saying that an out of focus image with camera shake is a “motion blur” rather than poor craftsmanship is simply dishonest.