Normalized flux vs. wavelength for four sample Fe I lines in an observed solar spectrum, together with model fits. Observations are shown as black circles, 1D LTE model fits are shown as red lines, and 〈3D〉 NLTE model fits are shown as cyan lines. Residuals for the 1D LTE and 〈3D〉 NLTE model fits are shown as red and cyan points, respectively. The points have been shifted by 0.1 and are plotted above each spectrum with a dashed line to indicate the zero point at 1.1.