Construction and programming of an autonomous focus stacker

Focus stacking is a technique of photomacrography and photomicrography that produces images of small three-dimensional subjects with an arbitrarily high depth of field, unencumbered by diffraction, by combining the in-focus portions of a stack of images of the subject recorded at different focal planes. Software packages are available for postprocessing an image stack into the final image, but the stack images are normally shot either with (typically expensive) automated equipment or by a manual, time-consuming, and error-prone procedures. This paper discusses the construction of an autonomous stacker with inexpensive preassembled electronics and a moderate amount of mechanical construction, and its C++ software.