Wednesday, October 10, 2007

Photo Tip: Overcoming camera shake at low shutter speeds

In addition to everything else I do, I am also an Assistant Scoutmaster for our church's troop. Tonight we did something very special. We retired an American flag.

Our church has over 100 temples worldwide. We are fortunate to have one in Atlanta, and Troop 566 had been asked to retire its flag. As fitting for a large building, it had a large flag -- 15 feet long!

We used eight Scouts in the effort to remove the old flag and hoist its new replacement. I was asked to document the whole event with photos, which was challenging since the sun had already set and by the time we were done it was quite dark.

Near the end of the ceremony, I wanted to get a photo of the new flag rising on the flagpole with the Scouts saluting it. I didn't want to use the flash because it would light up the parking lot in front of me but not add much light to the scene I was trying to capture. However, without the flash the shutter speed was registering around 1/10th of a second -- way too slow for the typical hand-held shot. And I didn't have a tripod.

So what did I do to improvise? I used my camera's high-speed frame rate. I have a Canon 20D, which shoots at five frames a second. Standing as still as possible, I held down the shutter button and fired off 13 shots in rapid succession. When I sat down at the computer to view them, five were in focus.

This is the best one.


The shot above was taken at 1/6th of a second with the lens set at f2.8 and film speed set to ISO 400. Pretty amazing!

So why did it work? No matter how still you try to stand, your body is still going to move and sway in tiny increments. If the shutter speed is faster than 1/50th of a second, it overcomes this movement. But if it is below 1/30th of a second, then you will suffer from camera shake.

By holding down the shutter button for several frames, the camera captured several shots when I was actually motionless -- in those split second moments when my body, arms, and hands were absolutely still.

Do you have to have five frames per second to do this? No. I have successfully done it on some of my older cameras that were at 3 fps. While I haven't personally done it with a slower frame rate than that, don't be afraid to try it with your point and shoot cameras, too. There's no harm done in trying!

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