Focus stacking is the technique of capturing multiple frames at incrementally shifted focus positions and blending them in software to produce a final image with greater depth of field than any single frame can provide. At 1:1 magnification, where a single frame at f/8 yields approximately two millimeters of sharp depth, stacking fifteen to twenty frames at overlapping focus intervals produces an image where several centimeters are in acceptable focus. This is not achievable any other way.