Surface brightness distribution for a stellar distance of 7.7 pc at a wavelength of 21 µm of the system n-i-M4, convolved with a PSF suitable for JWST/MIRI with the filter F2100W that has been obtained with the WebbPSF tool using a flat input source. To illustrate the PSF, a white circle is depicted in the lower-right edge with a diameter of 0.8″ (suitable for a wavelength of 21 µm and a telescope diameter of 6.5 m), similar to the used, more complex PSF. The red contour lines denote the regions succeeding the minimum surface brightness required to achieve a certain S/N when observing with JWST/MIRI for an exposure time of t_exp = 1 h. General figure characteristics are the same as in Fig. 9, and white contour lines have same meaning as in Fig. 13.