Electron microscope aberrations

Theory

The objective lens of the electron microscope imposes aberrations on the micrographs that should be corrected to obtain correct 3D reconstructions to high resolution. These abberations are typically modelled as a set of polynomials with various conventions (Table 1). The convention adopted in Bsoft defines the contrast transfer function (CTF) with a phase shift of gamma(s) as:

CTF in terms of aberrations
Aberration conventions table