Practical Electron Microscopy and Database

The coherence depends on both the origin of the electrons and their energy. The effect of the origin refers to spatial coherence or spatial incoherence, while the effect of the energy refers to temporal coherence or temporal incoherence. Therefore, electrons which originate from the same location but have different energies are temporally incoherent.

For modern median voltage TEMs, the Scherzer point resolution is lower than the information limit, which is controlled by the temporal coherence of the electron source.