most people leave the focus tied to the shutter. I do not. I focus with the focus button and NOT the shutter. that way I can focus on my subject and shoot whenever I want. You also dont have to know neccessarily where the subject will be, within the frame, so long as it's the correct distance away,(hence the pre focus) and you dont have to try to move the focus selector when the action is hot, or rely on the lens to keep up. However, nikon predictive auto focus is so good that many times the picute comes out in focus, even when it's not in focus in the viewfinder (predictive auto focus is another subject). If you leave the foscus tied to the shutter then the camera focuses when you push the shutter, and if it's not set to focus on the subject, you mis the shot becauce you just told the camera to focus on the image that's behind the focus point, and often it's not the subject, especially if the subject is moving fast or eraticlly.

My cameras have 9 independant focus points, but somtimes you cant move them fast enough to catch the action and if you push the shutter and it's directed to foucs on somthing in the background, you mis the shot again.

check your mannual. what kind of camera do you shoot?

The dog will NOT be out of focus if it's in the focus plane and you have enough shutter speed to stop the action. If you shoot at a slightly wider apature, you get more depth of field, and more chance of getting a sharp subject. If you can time it right, you can shoot f4 (with pre foucus) and get great backgrounds and a sharp subject.

if you can figure out how to turn the focus OFF the shutter and put it on the focus button, or the AE lock button than I'll bet once you get used to it, you'll never go back to shutter focus!

Takeing the focus OFF the shutter does not make it manual, it only moves the focus to an indipendant button. It still is auto, only, when you hit the shutter, it wont focus, it just activates the shutter. On my nikons it's a custom function and my vertical shutter release also has an independant focus button.

Check your manual.

Give it a try, if you shoot wildlife or action it's the only way to go. You also can hold the foucs button down and shoot only when you want a photo, all the while the subject stays in focus.

I hope that made some sence. . . .