Average error in the temperature, magnetic field strength, and line-of-sight velocity for the case in which a sinc² LSF is modeled with a Gaussian, when only one spectral line is used (630.15 nm), when the macroturbulent velocity parameter is let to vary in every pixel, or when there is a much lower spectral resolution (R = 5 × 10⁴) compared to the noisy degraded case (R = 10⁵).