By Aaron Raisey
Last time this column looked closely at the camera’s aperture and the effect different settings can have on images ― opening up the aperture for shallow selective focus, and closing it to get a deeper focus through the image. This week is a good idea to look at the aperture’s partner-in-crime: the shutter.
Just as the aperture is analogous to the iris in your eye, the shutter is a bit like a permanently closed eyelid, opening for brief durations to let light in and allowing the camera’s film or sensor to “see” and record an image. So by turning that DSLR’s dial another notch to ‘”time value” mode and explore what effect the different durations of the shutter’s journey from open to closed has on a photograph.
Usually photographers want a fast shutter speed to freeze the scene and resulting in sharp, in focus, images. Many modern cameras allow shutter speeds as fast as 1/8000 ― fast enough to freeze almost any action. Fast shutter speeds are great for sports and wildlife photography, capturing moments in time that may never be presented again. In a similar vein, capturing those kids’ precious moments at play often requires faster speeds as well.
But we’re all familiar with the camera recording a fleeting moment in all its sharpness for us to enjoy, but where the creativity lies is in the slower shutter speeds. As we increase the duration of the shutter, we can explore some interesting possibilities.
The longer the shutter is open, the more motion is captured on the film or sensor, resulting in the blurring of movement. This is (not surprisingly) known as “motion blur.” In practice, how can one use motion blur effectively?
Freezing a waterfall, for example, with a very fast shutter looks a bit unnatural _it is the motion that is attractive after all. Try a shutter speed of around 1/30 to capture flowing water at about the normal perception of the human eye. Dial down further to about one second or even longer to give the water a beautiful silky effect. Of course, a tripod is an invaluable tool when using a very slow shutter.
Panning is a cool technique that can be used on slower shutter speeds. Set a speed of about 1/2 to 1/15 and track a moving object such as a car or scooter while taking the photo. This will give the motion blur to the background, while (with practice) the subject remains quite sharp.
Also keep in mind that just as in Aperture Priority where the camera maintains optimal exposure by setting the shutter speed, in Shutter Priority the camera will automatically adjust the aperture to compensate for the selected shutter speed. The slower the speed, the smaller the aperture becomes, and as you know from last time, this affects our depth of field. Camera shake is a factor too. While most people can hold a camera reasonably steady for speeds of about 1/100 or faster, at speeds slower than this we might need to refine our hand-holding technique, or employ the aforementioned tripod.
Experiment with shutter speeds, and I highly recommend you try panning. But the most important thing you can do to improve your photography is to get out there and take more pictures. See you at the Seoul Photo club on Flickr.
Aaron Raisey is the leader of the Seoul Photo Club on Flickr (www.flickr.com/groups/seoulphotoclub), Korea’s premier expat photography society. If you have any questions or inquiries you can contact him at aaron.raisey@gmail.com.