Figure 1

Transmittance spectra for filters and spectral power distribution for lighting, screen guns and sorting pieces. Average transmittance spectra (in arbitrary units) of the filters (red lines for Variantor; blue lines for EnChroma; solid lines for filter to right eye, dotted lines for filter to left eye) in panels (a), (b) and (c) and average spectral power distribution (SPD): of the D65 light source (black dashed line) in panel (a); of screen guns of the Sony-GDM F520 (red dashed line for red gun; green dotted-dashed line for green gun and dark blue solid line for blue gun) in panel (b); and of the sorting pieces (black solid line with white circles for white pieces; blue solid line with blue circles for blue pieces; orange solid line with orange triangles for orange pieces; red solid line with red circles for red pieces; brown solid line with brown squares for brown pieces; green solid line with green crosses for green stimuli) as radiance in panel (c). Error bars indicate ± 1 standard error of the mean (SEM) across three measurements of filter transmittance and of the spectral power distribution (SPD) of the D65 light. If not visible, error bars in terms of repeatability of measurements from 400 to 730 nm are within the line/symbol size.