Loved it, gr8 flow to your work. I do love horse racing as well. What mode did you use with the canon 5d.
Its a shame they didn't use more aerial shots like directly over the top of the horse while doing track work.
These are HIGH spirited race horses, really don't like things out of place. We couldn't take a chance on flying over 15 million dollar animals and their riders. Not even once. We hid behind bushes and got pretty high before the horses came to the track, and our landing area was 500 meters away. Most of these shots were single shooter FPV flights. I only use manual mode with the focus to infinity. I can adjust the camera close enough for editing. Get better all the time. The funny thing is, we flew nearer and nearer to the animals everyday before we started filming, they got used to the machines flying around. A lot of work for 15 seconds of video. The horses were actually very curious. Almost as though they were wondering about the machines, wanted to get closer to them. After a few days, they would all come to the fence nearest where we were flying.