Specific intensity at the end of the growth phase (t = t_growth = 75 r_g/c) of a κ distribution with n_e = 5 × 10⁶ cm⁻³, B = 10 G, and κ = 4 for a range of Θ_e computed from the full fitting formulae of Pandya et al. (2016) (black curve) with the EMBLEM code (red dots) and with the high-frequency limit analytical expression (dashed blue curve). We overplot in light blue the range of Θ_e in which X_κ > 2000, i.e., where the relative error between the high-frequency limit and the full formula is lower than 20%.