I am saving up money to buy a Nikon 24mm prime lens for a D80 to use mostly for street photography. I see that I can buy a manual or autofocus lens but is one neccessarily better than the other? I understand that autofocus is better for some situations like action but will the manual focus lens generally produce a sharper image if focused right? An autofocus lens can be used manually as well, right? so does that mean the autofocus lens is always the better lens because it can do both?