All cameras are pretty quick if you pre-focus. This is done by pressing the button half-way before you take the shot. This engages the autofocus to lock on. When you see the moment then you fully depress the button...capture is nearly instantaneous with most cameras, even cheap ones. But if you want a sub-$200 camera that is fast when you do not pre-focus, then you want one with as little full autofocus shutter lag as possible.