Electron beam Objective lens Objective aperture (back focal plane) Fixed diffraction pattern) SAD aperture Intermediate image 1 Strength→ Intermediate change lens TEM Intermediate Intermediate 衍射及成像 diffraction image 2 pattern Projector 模式 lens Fixed strength www.globalsino.com/EM/ Diffraction Final pattern Screen image (a) (b) 10TEM 衍射及成像 模式 10