(*TEST* flat inverted) --- filter V, bin 2, night 220125, compared to previous night 211128, sigma = 0.2621 --- (flat / previous inverted)
(flat inverted) --- filter B, bin 2, night 211209
(flat inverted) --- filter SG, bin 2, night 211108
(flat inverted) --- filter SI, bin 2, night 211209
(flat inverted) --- filter SR, bin 2, night 211108
(flat inverted) --- filter V, bin 2, night 220125