Sigma DP2s, ISO 50, f/6.3, 1/8 sec.
There are three approaches to action photography.
The first approach taken by most users of "consumer grade point-and-shoot cameras" is that of holding down the shutter button while you point the camera at approximately the right spot while you follow the subject.
The second approach taken by most users of DSLRs, is that of holding down the shutter button while you point the camera at approximately the right spot while you follow the subject.
The difference between these two approaches is that the point-and-shoot user ends up with four bad frames and the DSLR user ends up with ten bad frames.
The third approach treats the scene with respect, immerses oneself in it, and pretends that the only photo you're going to take is the last one you're ever going to take, so make it good.
I've watched countless boaters float the Gallatin River's House Rock Rapid in the past 17 years. Having packrafted it myself numerous times, I know its ins and outs and bumps and splashes.
So when I was driving down the canyon last week, and saw some boaters coming through, I knew exactly what I wanted to capture: all of them looking downstream and hopefully, with a little splash coming over the boat. I took a few frames to get the exposure correct, set the shutter speed to 1/8 sec., and got ready to pan.
Before the boat hit the top of the rapids, I started panning at the boat speed, which is a little slower than the water speed, waited for the boat to enter the upstream third of my frame, waited for the boat to enter the rapid, then waited for everyone to look downstream, then clicked.
I like shooting this on a camera with an optical viewfinder, and with both eyes open. I use the little Sigma VF-21 viewfinder on my DP2s, but wished I had the far better Voigtlander 40mm viewfinder, which offers greater eye relief and more visible frame lines when both eyes are open.
I got lucky with the scared guy in the back of the boat. Right before I started panning, he lost his paddle. You can't plan these things better!
I just wish I could zoom in to see his knuckles.