There are many reasons to alter shutter speeds. A fast moving object could become blurred at lower speeds and slow speeds are frequently used to give running water a soft cotton wool like effect’ foe example. Movement blur is not always a bad thing and when a moving subject such as a runner or car is totally frozen by a high shutter speed, the results can look very static. A sense of movement will be conveyed if there is some blurring in the athlete’s limbs or the vehicle’s wheels.

There is another technique called panning, where a shutter speed as low as 1/30 or 1/15 is set. When the shutter is pressed, move the camera in the same direction as the subject so that it stays in the same place in the frame. It takes practice to perfect, especially with a DSLR where the mirror blanks out the viewfinder during an exposure. When it works, the subject will be sharp with the blurred background implying movement. If using a lens or camera with image stabilisation, set it to detect camera movement in the vertical plane only, otherwise the system will attempt to make unwanted corrections as the camera pans horizontally.

This image was taken with a shutter speed of 1/15th second, which has caused blurring to the figures on the left and given them a sense of movement. That the rest of image is sharp in this handheld shot is due to the camera’s inbuilt image stabilisation.