Normalised model spectra with respect to the mean flux for (red), 10⁻⁵ (green), 10⁻⁶ (blue), and 10⁻⁷ M_⊙ yr⁻¹ (purple). We also plotted the spectra and visibilities based on the MARCS model without a wind (orange). This is the case for R.E. We have convolved the results with the spectral resolution of R = 1000. The main differences within models can be seen in the water, CO, and SiO molecular bands, the corresponding wavelength regions are highlighted in light grey.