This book (Practical Electron Microscopy and Database) is a reference for TEM and SEM students, operators, engineers, technicians, managers, and researchers.
 

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If the TEM specimen is very thick, both the chromatic and spherical aberrations affect the spatial resolution of EFTEM imaging significantly. For instance, for thick specimen the chromatic broadening (Δd_c) is about 2.5 nm at β = 10 mrad, C_c = 1 mm, ΔE = 50 eV, and E₀ = 200 keV, while for thin specimen, Δd_c will be normally ≤ 0.2 nm for most microscope configurations (see details in page3384). For thick specimen, assuming the spherical aberration constant is 0.7 mm, collection semi-angle 15 mrad, the Δd_S will be ~3.8 nm, while for thin specimen Δd_S is normally negligible for most microscope configurations (see details in page1941).