Dependency on . Upper part: panels from top to bottom display “infinite”-resolution images of models with , (15,20), and (25,20) at a viewing angle i = 90°. Left, middle, and right columns show the model appearance at λ = 13, 7 and 1.3 mm, respectively. Colors code the radiation intensity on a linear scale. The field of view of the left and middle panels is 200 × 200 GM_BH/ c² (approximately 1 × 1mas), and the right panel’s field of view is 20 × 20 GM_BH/ c². Lower part: spectrum emitted by the various models. The normalization is marked with a black point.