What is focus stacking When to use Rail vs lens stacking Rail changes the camera location. The focusing distance stays the same. It works well when shooting an object that is elongated. The blur can create a glow effect if not well controlled. This is usable only in macro and microphotography. Lens stacking changes the focus plane location. It works will all subject great and small. Notice that when shooting for macro or microphotography focusing manually is difficult in macro and nearly impossible in micro.