Intensity cross-sections across the core region of 3C 84 at 5 GHz. The second and third panels from the left show the CLEAN image (0.6 × 0.3 mas at 23°) and the EHTIM (MEM = 0, TV = 1, TV2 = 1, L1 = 1; see Appendix C for an explanation of the parameters) image, both in logarithmic colour scale with the analysed cross-sections overlaid. The left panel shows three examples of CLEAN image cross-sections with Gaussian fits. The right panel again shows three examples of EHTIM cross-sections, where the black dots are the pixel intensities, the blue curve is the Gaussian-smoothed intensity cross-section, the magenta curve is the first derivative of the smoothed cross-section, and the red curve is the second derivative of the smoothed cross-section.