SUMMARYSingle atom image intensities are calculated for bright‐field and various dark‐field modes, including the ideal beam stop, a wire beam stop, tilted illumination and a displaced aperture. Comparisons of scattering amplitudes and elastic scattering cross‐sections are made with different object potentials and scattering formulations. The image contrast for one mercury atom (Z= 80) on a column of carbon atoms (Z= 6) as the substrate is also discussed for both the bright‐field and the various dark‐field situations. A list of abbreviations to be used in the text is sh