This lecture explores the dynamical scattering effect of thickness fringes in bright-field and dark-field Transmission Electron Microscopy (TEM) images. The instructor discusses the 2-beam dynamical scattering intensity,everal equations and conditions related toy, and the intensity vs. thickness plots. The lecture also covers the s-function of thickness fringes, weak beam imaging, and a summary of the dynamical effects observed in TEM images.