Originally Posted by rik
These kinds of action shots are not so difficult. Focus is no problem. Only the shutter speed. You need at least 1/640. If there is not enough light increase your ISO. Each time you double the ISO (for example, from 100 to 200), the camera needs only half as much light for the same exposure. If your shutter speed is is 1/320 with iso 100 it will be 1/640 with iso 200 and 1/1280 with iso 400.
If the dog or whatever moves fast in your direction it needs a different approach.
I use the continuous focus on my Nikon (AF-C) (Canon it is Al Servo AF). It keeps moving objects sharp within the viewfinder as you track the object.
If your camera do not have a continuous focus you can try this;
If the movement is predictable you can manual focus on that predictable point and press the button if the object (dog) is at that point.
(Continuous focus is much easier
They're great shots ,I guess you would need a steady hand too which I do not have anymore.