This webpage presents the originally published (V1.0) TEM ray diagrams with the condenser aperture at the level of the C2 lens. While this usefully describes ray selection by the condenser aperture and is aesthetically pleasing, it is less physically realistic than placing the aperture below the C2 lens, as done in the updated ray diagrams.
TEM Ray Diagrams @ 2025 by Duncan T.L. Alexander are licensed under CC-BY 4.0.
- TEM image mode, direct beam
- TEM image mode, one diffracted beam
- TEM image mode, two diffracted beams
- TEM bright-field image mode
- TEM dark-field image mode
- TEM diffraction mode, one diffracted beam
- TEM diffraction mode, two diffracted beams
- TEM selected area diffraction mode, with two diffracted beams
- STEM mode, with direct beam
- STEM mode, with direct beam and one diffracted beam