This book (Practical Electron Microscopy and Database) is a reference for TEM and SEM students, operators, engineers, technicians, managers, and researchers.
The electron-beam-tilt-induced image displacement in TEM can be given by, 
w = α exp(iϕ) ------------------ [1914b],
Cs -- The spherical aberration coefficient,
z -- The defocus (the difference of TEM specimen height from the standard focus height),
a2 = A2 exp(i2ϕ2),
b = B exp(iϕB),
a3 = A3 exp(i3ϕ3),
α -- The scattering angle,
A2 -- The two-fold astigmatism coefficients,
A3 -- The three-fold astigmatism coefficients,
B -- The coefficients corresponding to coma displacement,
ϕ2, ϕB, and ϕ3 -- The initial phases of corresponding aberrations.
The overbar in Equation 1914a denotes a complex conjugate. Equation 1914a represents the image displacement terms related to spherical aberration, defocus, two- and three-fold astigmatisms, and coma.
One of the most commonly used autofocus methods in TEM is based on a beam-tilt induced image displacement . This method is especially applied for life-sciences.
 Koji Kimoto, Kazuo Ishizuka, Nobuo Tanaka, Yoshio Matsui, Practical procedure for coma-free alignment using caustic figure, Ultramicroscopy 96 (2003) 219–227.
 A.J. Koster, A. van den Bos, K. van der Mast, An autofocus method for a TEM,
Ultramicroscopy 21 (3) (1987) 209–222.