High-resolution observations of the Ti I 5713.9 Å line as a detailed view of Fig. 2. The quiet Sun spectrum (blue curve) and umbral spectrum (red curve) are compared with the emission spectrum from the hollow cathode lamp (HCL, black curve). While both solar spectra were normalized to the continuum level, the lamp spectrum was adapted in intensity to allow a better illustration. The center positions of fits to the line core are marked as blue dashed (quiet Sun), red dashed-dotted (umbra), and black dotted (lamp) lines.