Left: independent segment requirements as calculated with Eq. (12) for target contrasts of Δc_t = 5 × 10⁻⁷ (top, blue) and Δc_t = 3 × 10⁻⁷ (bottom, orange). These numbers are the standard deviation of the tolerable WFE rms on each segment if the target contrast is to be met as a statistical mean over many realizations of the segmented mirror. The range for the 5 × 10⁻⁷ target spans from 2.5 to 6 nm. Both curves show a clear jump in the outermost ring (starting with segment number 19), which is highly concealed by the LS (see Fig. 2). Right: tolerance map for a target contrast of Δc_t = 5 × 10⁻⁷, shown in blue on the left. The global left-right asymmetries are due to a slightly offset LS, which does not impact the contrast performance at this level but is visible in the segment sensitivities. The map for Δc = 3 × 10⁻⁷ is a scaled version of the one shown here.