Effects of decreasing spectral resolution on line profiles (axes at the bottom) and their bisectors (tenfold expanded axes at the top) for a representative spectral line. From the top down, three rows show the Fe I λ 539.8286 nmline for λ∕Δλ = 300 000, 150 000, and 75 000. Left column: data for integrated full-disk flux. Right column: for stellar disk center (μ = 1). The same Fe I line is shown in models for ‘F3 V’, ‘F7 V’, and ‘G1 V’ as short-, medium-, and long-dashed lines (red, green, and blue). Each frame also shows profiles and bisectors at the original hyper-high spectral resolution, marked as dotted gray and solid gray curves.