One aspect of photography that is often misunderstood is that when you take a picture you are not capturing an instant but rather a period in time. During this period things happen and the choices you make when taking your picture will fundamentally change the results you get. Movement in photographs should be captured deliberately, making sure that it looks like that was the plan. A picture that is just a little blurred will usually look just that, a little blurred.
Any camera can capture movement but the amount of control you have will determine the amount of movement that you are able to show. The longer the shutter speed the more movement can be captured.
For most pictures featuring movement you should use a tripod but there will be times when just shooting plenty of pictures hand-held will be a better strategy.
The technique you need to adopt will depend upon what you are trying to say. Digitally you can shoot and review what is happening and if the movement is too much use a faster speed; if they are too ‘static’ use a slower speed. Typically you should try shooting at about 1/15th or 1/30th with a reasonably fast subject. Panning can be done on a tripod, but the results will be quite different. It is essential if using a tripod (or monopod) that the camera should be able to follow the action accurately, if the moving action is at an angle to the camera movement you will struggle to get usable pictures.
However, this doesn't mean you have to keep the subject sharp. In this shot of the Tour de France nothing is really sharp, but there is a clear difference between the blurriness of the crowd and the slightly sharper rider and this makes the picture more dynamic.
Sometimes it is not necessary for the camera to be moving at all. Fixing the camera on a tripod and letting the subject move will give an altogether different result. This same technique can be used at night to get car lights on the roads which can be a very effective way of showing movement. Machinery is also a good source of subject as they often look much more interesting in action than at rest – or frozen with flash.
In some situations, flash can be used though; if you set the camera to slow-sync you can have the combination of a blurred image with a sharp one overlaid on it. If possible set the camera to ‘rear’ or ‘second curtain’ sync or the subject will appear to be moving backwards.
Whatever you approach though try and make the movement you capture say something about the subject – that is what will make the picture work.