Movement

I wanted to experiment with shutter speeds so took my long suffering other half and car to a local car park where he could drive up and down for an hour or so (without getting arrested!) whilst I took photos. I started by seeing how the shutter speed affected the amount of blur as the car passed a locked down camera, and then tried the same thing while panning. See below for the effects.

Experimenting with motion blur

For the first half of the exercise I fixed my camera on a tripod and pointed it at a position where I could capture the car as it went past. I set my camera to shutter speed priority (that’s the Tv mode, in Canon-speak) so I could change the shutter speed whilst the exposure remained constant.  I took twelve images in all ranging from 1/4000th of a second to 1/2 a second, while Ian drove past at a constant speed for each image. Here are the four most interesting.

Image 1: This was taken with a shutter speed of 1/500th of a second. This was the slowest shutter speed where the movement was sharply frozen (Ian was driving past at around 10 mph).

Image 2: This was taken with a shutter speed of 1/60th of a second. Motion blur is becoming obvious.

Image 3: This was taken with a shutter speed of 1/30th of a second. Motion blur is very obvious.

Image 4: This was taken with a shutter speed of 1/8th of a second. At this shutter speed the car appears to be going very fast (remember though it was only doing around ten miles per hour). The exposure had also become to great for the camera to cope with at the smallest possible aperture, so the picture is overexposed even at ISO 100. I also noticed an interesting effect in the wheels caused by the changing position of the reflected highlights as the wheels turned during the longer exposure.

In doing this exercise I learned that to freeze movement you need a fairly high shutter speed, say 1/500th or faster. The slower the shutter speed the more blur you get. However a very slow shutter speed can let in too much light for the camera to handle. For a usable image at these very slow shutter speeds a filter would be required to block some of the light.

Experimenting with panning

For the second half of the exercise I removed the camera from the tripod and hand-held it whilst following the movement of the car, again traveling at around 10 miles per hour. I took twelve images in all, ranging again from 1/4000th of a second to 1/2 a second. Again the four most interesting images:

Image 1: This was taken with a shutter speed of 1/60th of a second. The car is sharply in focus and the background is just starting to blur.

Image 2: This was taken at 1/30th of a second. Here the car is reasonably in focus but the wheels are starting to blur. The background is obviously blurred but the impression of speed isn’t very strong.

Image 3: This image was taken at 1/15th of a second. The background is nicely blurred giving a good impression of speed in the background and the wheels, and the car is still reasonably sharp.

Image 4: This image was taken at 1/8th of a second. Although the background is even more nicely blurred the shutter speed is too slow to be able to keep the car in focus, and the image has broken down into an abstract.

Whilst panning, the slower the shutter speed the more motion blur you get. Above a shutter speed of 1/60 of a second it didn’t look like the car was moving (of course this car was moving slowly – if it had been moving faster the 1/60th shot might have produced a good background blur as I would have had to pan more quickly). However when the shutter speed is too long you can’t keep the subject in focus and the desired effect is lost.

#car #focus #motionblur #speed