Rapid autotuning for crystalline specimens from an inline hologram.

A method to measure the aberration function for a crystalline specimen from a single inline hologram or 'Ronchigram' by dividing it up into small patches is derived. Measurement of aberrations is demonstrated from both dynamical simulations and experimental Ronchigrams. This method should allow rapid fine-tuning on a variety of crystalline specimens and represents a key step toward active optics for scanning transmission electron microscopy.