Higher magnification objective lenses generally have shallower depth of field; a 100× objective lens with a numerical aperture of around 1.4 has a depth of field of approximately 1 μm. When observing a sample directly the limitations of the shallow depth of field are easy to circumvent by focusing up and down through the sample; to effectively present microscopy data of a complex 3D structure in 2D, focus stacking is a very useful technique. Atomic resolution scanning transmission electron microscopy encounters similar difficulties, where specimen features are much larger than the depth of field. By taking a through-focal series, the depth of focus can be reconstructed to create a single image entirely in focus.