in a split second, trust your shutter is set fast enough, and capture the image before it’s too late.
i must offer a final note of caution regarding super fast shutter speeds. whenever you get all the way up to 1/1500s, your shutter speed is so fast that it will seriously limit the amount of light making its way to your camera sensor. it will be fine on a bright sunny day, but i would advise you to check your light meter and take some sample photos first. don't use these fast shutter speeds in the early morning, evening, or during the fall. there just won't be enough light getting in 