Electron diffraction data acquisition. (a) Measured powder pattern of an aluminium diffraction standard after correcting for the tiling offsets of the Timepix quad ASICs. An elliptical distortion can be observed with a deviation of 1.043 (= A/B) at an angle of φ = 21.3°. Diffraction from the single lysozyme crystal summed over 1.0° of rotation (b) from ?17.0° to ?16.0° and (c) from ?6.0 to ?5.0°. Crosses on individual quads are owing to corrections for larger border pixels as described by Nederlof et al. (2013) and van Genderen et al. (2016); these pixels were not taken into account for processing of the protein diffraction data. Note that owing to the radiation hardness of the detector, no backstop was required. Resolution rings were plotted with ADXV. (d) A typical spot profile of a high-intensity peak at 16.33?? resolution recorded on a single frame with an angular increment of 0.076° per frame at a dose rate of ～0.01?e????2 per frame, shown in a 10 × 10 pixel array with 0.055 × 0.055?mm pixel size. [Clabbers, M. T. B., van Genderen, E., Wan, W., Wiegers, E. L., Gruene, T. and Abrahams, J. P. (2017). Acta Cryst. D73, 738-748. doi:10.1107/S2059798317010348]