I was in Wyoming staying at Absaroka Ranch near Dubois. I was able to get a lot of pictures of horses running with and without cowboys/cowgirls on them, usually at top speed. For every shoot, I set my camera at shutter priority 1/500 and everything else auto, which I never ever do normally. But in this case, when a herd of horses is running by you and the whole episode lasts only a minute or two, you don’t have time to check that you’re getting good pictures. You set your camera to high burst and let ‘er rip. In two minutes, you can get a lot of pictures, and you’re going to get some throwaways and keepers. I was lucky enough to get enough keepers to make me happy. This is one of them. I kept my Canon 5D Mark III and my Canon EF 100-400mm f/4.5-5.6L IS USM Telephoto Zoom Lens on one shoulder and my Canon 60D and Canon EF 16-35mm f/2.8L II USM Ultra Wide Angle Zoom Lens hanging from my other shoulder, both set to 1/500 and auto everything else. That way I could drop one and grab the other depending on the action.
For this picture, I used the 5D camera and 100-400mm lens. Camera settings in this photo are 1/500 shutter speed, ISO 100, 170mm, and f5.6.