English: Selected area electron diffraction (SAED) pattern of a thick Si specimen with many diffusely-scattered 100keV electrons, and a beam direction nearly parallel to the Si<111> zone.
The λ ≈ 0.0370 Å electron-wavelength makes the radius 1/λ Ewald-sphere nearly planar on the scale of the inner-star radius g220 ≡ 1/d220 ≈ 1/1.92Å, and the beam half-angle facilitates weak excitation of many Bragg-reflections even though no reflections are at the Bragg-condition (where a Kikuchi-band in the star-pattern e.g. of width θscatt = 2θBragg = 2asin[λ/(2d220)] ≈ 19.2 mrad would have been shifted to intersect both the incident beam's central dot and a diffraction spot).
These electrons either had enough leptonic-imagination
by themselves to construct the 2D Wigner-Seitz cell
[1] (lattice-point bisectors) for this reciprocal-lattice slice, or else Brillouin-zone surfaces in a crystal are so real that they can be directly imaged. What do you think?