Practical Autotuning for Transmission Electron Microscopes
There are three main algorithms for autotuning a transmission electron microscope (TEM), (1) image variance method, (2) tilt-induced image shift (TIS) method, and (3) automated diffractogram analysis method (ADA). In practice, each method has its own advantages and limitations. Therefore it is necessary to obtain a comprehensive understanding of each in order to be able to select the most appropriate one(s).There are four key elements in any TEM autotuning setup, (1) microscope control by an external computer, for example via the standard RS232 serial port; (2) proper image acquisition device, for example a TV or a slow-scan CCD camera; (3) appropriate software for image analysis, processing, and optimization; (4) a fast computer that is the central control unit in the setup and dictates all the activities and operations.