Comparison between Fourier spectra from Doppler-determined velocities and from vertical velocities on constant-τ₅₀₀ surfaces, both obtained from the simulation data. Red: velocity spectra from the MHD 100 G data using Doppler shifts in the synthetic observation. The data have not been convolved spatially with a PSF nor, spectrally, with an MSRF. Black: velocity spectrum for the vertical component of the velocity taken directly from the MHD 100 G data cube on the log (τ₅₀₀) = −1 surface. No p-mode filtering has been applied to obtain this figure.