152/366: Fun With Motion Blur

This one was a whole bunch of work for one smallish shot...

So, in past rounds of "science-y things with my fancy camera," I looked at the effect of ISO settings and apertures. This time out, I wanted to look at something moving, and the way that it blurs with increasing exposure time.

My initial thought was to try to take pictures of a falling ball, but it's too hard to get that to work consistently without setting up some kind of electronic trigger, and I wasn't willing to do that. But, of course, a swinging pendulum will always be in a relatively narrow range of positions, making it a better moving target.

So, the composite below is a bunch of shots of a yo-yo hung from the ceiling in our basement, swinging back and forth. The focus was set to manual, the f-stop maxed out, and I adjusted the shutter speed and ISO level to get approximately the same exposure each time. I got it in nearly the same position each time by the simple expedient of holding down the shutter button in continuous shooting mode and hoping for the best.

Composite of a swinging yo-yo shot with different exposure times. Composite of a swinging yo-yo shot with different exposure times.

The colors are kind of wonky because I couldn't find the dark blue plastic yo-yo we have somewhere, only one that's clear plastic with writing on it. At the longer exposures, that's blurred out enough to be nearly invisible without cranking the contrast way up.

I may re-do this at a later date, just to get cleaner images, but this is a decent proof-of-principle for the effect I wanted. It's kind of impressive to me how fast the shutter can be and still produce significant blurring-- this is only moving at a few meters per second, and yet there's very definite blurring at a shutter speed considerably higher than the standard video frame rates.

Anyway, that was fun. And as a bonus, it explains why so many of my photos of the kids look kind of fuzzy...

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