Motion capture...

[Rumbleman]

So I've been trying to understand the technicalities in capturing motion, but I haven't had any luck trying to teach myself. I'm mostly looking into trying to capture sports. What is the key? Faster shutter speeds? Higher apertures? Explain how to adjust it in reference to good or bad light. I couldn't find anything on it in the sticky up top.

Sean

[engstrom]

A fast shutter speed freezing the action is what's normally used in sports shooting. The problem is that fast shutter speeds in low lights require large apertures and when you combine that with the long focal lengths needed to capture the action for pro sports you end up with big heavy expensive lenses.

The good news is that if you're taking pictures of your kids you can get close and hopefully they'll be playing when the sun's out. That mean you should have a relatively easy time cranking the ISO up a little and getting fast shutter speeds to freeze the action.

Of course isolating the subject with a narrow depth of field is another advantage of long focal length large aperture lenses, but unless you have money burning a hole in your pocket I would concentrate on timing, composition, and processing before looking at getting better lenses.

Oh, one more thing - I personally like a little blur in some of my sports shots. If I can get a little blur on a football/baseball/soccer ball but keep the subject tack sharp and frozen that gives a sense of motion to the picture. You can play around with slowing down the shutter speed and seeing what works for you.

[toverman]

Car racing is a good example where you want sharpness and motion in the wheels at the same time. You don't want such a fast shutter that it looks like the car's not moving. One way to get dynamic car shots is to pan, using a slow shutter and tracking the subject across the frame. Works on a different level with fast-moving people, too, and is one way to overcome bad light while getting good shots.

Lenses used for sports usually have a max aperture of at least f/2.8, which will allow faster shutters in questionable light but also help isolate the subject from the background (as will the longer focal lengths typically used, often 300 and up).