The World As I See It: Shutter Speed

February 2, 2014

Shutter Speed

Yesterday I went in search of some Bald Eagles, knowing that the odds would be slim that I'd see any. I saw one. Flying away from me. Far, far away. Other than a few ducks and some seagulls, there wasn't much else around. As I was headed back to the main road, I came upon a couple of guys prepping their air-boat to head out into the bay. I stopped and watched them, because I knew they would be headed down the main channel, I thought it might make for a good shot. While waiting, I decided that the spinning prop on the boat would make a good example on the effects of shutter speeds.

So, I grabbed my 5D Mk III with the 70-200 f/2.8L IS II set it to Tv (shutter priority) and auto ISO. I started at 1/8000 sec and took a shot at each click, all the way down to 1/4 Sec. I've included images at full stop increments to illustrate the difference.

Take a close look at each of the images and pay attention to the amount of motion blur in the prop. You can see at 1/8000, the motion of the prop is stopped completely. At 1/2000, you can start to see the motion. At 1/1000, the motion is noticeable, and get progressively more apparent form there. By about 1/30 sec, the prop all but disappears. At 1/4 sec, it's difficult to make out the outline of the spinning prop.

And, just because I want to make sure that you get your money's worth, take a close look at the depth of field as we move from f/2.8 in the first image to f/32 in the last. It's especially noticeable if you watch Antelope Island in the background.