Learning to film people running seems to be a skill within itself. When I set out to make 6 sets of one minute films all around running and the wisdom it holds, I knew that I should expect a few new problems.
Firstly, it is very hard to get any amount of usable footage when someone is tearing past your camera. It is also quite impossible, unless you have a proper Steadicam and vest setup and a skilled Steadicam Operator to follow a runner in front or behind. I have filmed two of these 1 minute pieces so far and would like to offer my own humble learnings. I am aware that there are probably more detailed and better techniques out there somewhere.
1) Use a car: For this little piece I sat in the boot of the car with the door open while Kevin drove and the runner ran behind the car. The motion was incredibly smooth and I could zoom in and out for a varied shot. I was using a Canon EF 24-105mm f/4 IS USM lens. I have a 50mm lens that does not have image stabilisation but I don't use it for anything other than shots that I can do on tripod or on the floor or some kind of steady surface. Since I knew the car would be very 'moving' I wanted as much stabilisation as I could get. I did this version handheld but it would be good to test it with the Merlin Steadicam.
I also got similar side running shots by sitting in the back seat and asking the runner to run alongside the car, while I stuck my camera out the window and got a nice medium shot driving alongside them. The camera lens can also balance on the window frame which keeps the shot nice and steady too. It looks nice and it's lovely to get the continuous motion of the running without losing the runner.
2) Don't be afraid of the old fashioned pan: Don't turn your nose up to just sticking the camera on a tripod and panning with the runner on a wide or medium shot. I think sometimes I get to fixated on cool moving shots and always being in the action, but you know sometimes our tired eyes just want to watch the action slowly unfold.
3) Lose focus: Again don't be afraid to start or finish out of focus on the runner. By that I don't mean just give up and don't focus! I do mean that if you have a steady shot which your runner runs in or out of, pick a focus point and don't change it during the shot. It all happens so quickly it will be more confusing if you follow focus and the runner running off into blur with grass in focus in front of your lens (or the other way round) can looks quite arty and pretty.
4) Ask your runner to slow down if necessary: Sometimes, for some shots, a split second faster than a walk is what you need to get the shot you want. It's ok. They don't have to be running for it to look like running. Film is mostly about cheating the eye and the brain.
5) Get some close up shots: It is tempting to not get medium close and close up shots with running because everything happens so fast and the action moves by you so quickly. I found that most of my shots were starting to be medium wide, medium slightly wider, medium sort of wide. So I made sure that I had some close ups to cut to for editing. These don't have to be running. This could be the runner putting on their shoes for the run, stopping for a breather over a beautiful landscape, walking to the run or even the landscape itself: a flower, a gate, a rabbit in the grass (if you're lucky) Just bits and pieces of closer, steady shots you can cut to amid all the moving wide shots.