Fig. 11

Spatio-temporal sRGB renderings of the lantern, for D65 illuminant and 2\(^{\circ }\) observer. For simulating the past, we reverse the light exposure, up to − 1.19 Mlux hr (equivalent to − 341 s or k = − 31 time steps). Present refers to 0 Mlux hr (k = 1) and future to + 1.19 Mlux hr (k = 32 or + 341 s). We can see that the overall appearance turns darker due to photodegradation. Also we can notice the shift to greener hues of the orange colours in the center (corresponding to points O1, O2, O3 in the microfaded samples). For a more gradual display of the change, for intermediate time steps, please watch the animation in the Additional file 1