How to give the illusion of movement…
Capturing movement in video is similar to capturing movement in photos. The above image of Jenson Button doesn’t show the viewer how fast Jenson is travelling. As the photo is a still frame the only indication the viewer has on speed is any motion blurring. In this image (taken on my iPhone) the only part with any blur is the logo on the wheels. Without this blur Jenson may as well have been stationary.
How does this apply to video?
Of course the above problem isn’t quite the same in video production as Jenson would have been moving through frame showing how fast he was going. Correct. But wrong!
Shutter Speed is the primary setting in discussion. Taking the above image as an example, if the shutter speed was faster then there would be no blurring on the tyres. If the shutter speed was slower then there would be more blur in the image (depending on what is moving) for example you could move the camera with the car and make the car sharp and the background blurry, thus showing the movement.
This is the same in video. If you shoot this scene with a fast shutter speed then the smooth flowing motion will not be pleasant to look at, it will look like a bunch of sped up photos. If you shoot with a slower shutter speed then the background will blur as you follow Jenson around this corner. A balance for an experienced camera operator to play with!
Why is this relevant?
Not so long ago most camera operators would only adjust the shutter speed of their DV video camera if they are filming TV screens, computers or lights. Now however on DSLR’s it is often necessary to increase the shutter speed so the aperture can be opened up, thus making this relevant! If you were to shoot the above scene I would recommend using the correct ND filters so that you can keep the shutter speed where it should be!