ABSTRACT
Confidence in the interpretation of an image from an unknown structure is established by reference to known structures and their images. It is the experience of the microscopist that translates these images into the possible three-dimensional projections of objects. Since the specimen is thin and transparent, density and crystal orientation variations within the specimen have to be considered when interpreting the image. Images formed with transmitted electrons contain information about specimen structure and composition. However, in the scanning transmission electron microscopy (STEM) especially, at low magnification, there may be some contributions from the detectors themselves forming a kind of background pattern that needs to be understood before it can be ignored. The size and shape of the probe in a STEM are determined by the source, beam-defining apertures, the electron energy, and the settings and quality of the probe-forming lenses.
