Movement
This photograph was also taken from a moving vehicle. I used a shutter speed of 1/25. However, instead of using a 18mm DX lens, I used a 70mm-DX lens. You can notice how this picture shows more movement than the previous one.
I took this photograph using a shutter speed of 1/30. Even though the image is quite frozen, you can see some movement.
Another effect we can get when using low shutter speeds is the effect of "sweep". To achieve this, we need to move the camera in the same direction the object is moving to. As a result, going back to the previous example, if I were standing next to the highway and the car I want to photograph runs by, I would have to follow the movement of the car with my camera. In order to be able to achieve this, we would need a very low shutter speed: 1/2, 1’’, 2’’.
If the camera is moving at the same shutter speed as the object, the result would be a frozen object and a moving background. This effect is very common in sports, specially car races. Why? Because the car appears frozen (this lets us know which car it is) but, since the background is moved, it will give us the sensation of "speed" or movement. If both the car and the background were frozen, it would seem as if you took the picture while the car wasn't running, but steady.
This is very hard to achieve and it requires lots of practice. We need to take many pictures and lots of luck. With a telephoto lens, we need to move less to achieve the same effect than with a shorter lens.
