Photo Tip #9: Motion Blur

Hello ... and long time no see. Or write, and I do apologize. Is it really October? I nearly missed by Dad's birthday this week ... time flies when we don't pay attention. And there isn't enough of it to be wasting it - time that is.

Yesterday around 5:00, after an afternoon of staring at the computer while the beautiful fall sun was shining something amazing, I grabbed the camera for a quick stroll along the Riverwalk. Now, I know that my colleague Shannon Szwarc does wonderful work on the Chattahoochee with sweet shots of kayakers and skateboarders and birds hanging out on the rocks (see his blog at http://riverwalkingcolumbus.blogspot.com/), but I decided to quickly photograph the kayakers anyway - to show how shutter speed can be used to allow for 'motion blur.'

If you have a subject that is motionless, or you tell your subject to remain motionless, you can slow your shutter speed to allow other elements in the frame to be in motion long enough to create a blurry motion around the subject. These guys weren't quite skilled enough to stay motionless as they surfed the white water -- but then -- that's what they were practicing, so I can't complain.

The first shot was taken at 1/30th of a second. You can see the white water has a smooth appearance. The guys were resting. Go slower though, using a tripod, for an even smoother, almost ethereal feel. I didn't have a tripod with me, and I can't hand hold a long lens at 1/20th or slower.

The second shot is at 1/80th of a second. The kayaker is moving too fast to be 'captured,' or stopped, by that slow of a shutter speed. And the water just looks blurry. The shutter speed is too fast for the water have a smooth feel, and too slow to be crisp. It's too slow to 'stop the action.' And I might have some camera shake.

The third shot is at 1/125th of a second. I caught the kayaker as he is momentarily motionless on the wave. You can see that the water is becoming a bit more sharp. Obviously, to stop fast moving water and capture crisp splashes and droplets and waves, we need a fast shutter speed. The faster the better. Start at least with 1/500, but 1/1000 or faster is better.

Which is the shutter speed that Shannon used to shoot this last kayaker. (Something distracted me, and I didn't go back to shoot at 1/1000. My bad.) Notice the water splashing off of his face, and the streams and drops off of the paddle. Stopped, or frozen, movement.

Now remember, as you increase your shutter speed, you must decrease your aperture to keep an accurate exposure. And as you open the aperture, you lose depth of field -- so stay tightly focused on the subject. Or increase your ISO, which will then give you more shutter speed at small apertures, or a smaller aperture for greater depth of field if you so desire. So, this also became a quick review on how ISO, aperture and shutter speed work together.

Shoot some waves!
Robin