Fig. 11

a–c Comparison of spectra obtained on the left and right side from the pair of datacubes recorded in the morning, for three selected colors (green, purple, and red). d–f Comparison of spectra obtained on the left and right side from the pair of datacubes recorded in the afternoon, for the three selected colors (green, purple, and red). The bands’ position of the main chromophores (np = nanoparticles) are indicated with arrows, except for Fe²⁺. Since the maximum of the Fe²⁺ band falls outside the camera spectral range (1100 nm), and the NIR region is quite noisy, it was preferred to indicate the band width for this chromophore. The small peak at 750 nm in a and d is an artifact probably due to the sunlight spectrum or interference from atmosphere. Postfixs in curve labelling: l = left; r = right. Figure 10 shows the points where the spectra were taken