(*TEST* flat inverted) --- filter SG, bin 2, night 210419, compared to previous night 210407, sigma = 0.0134 --- (flat / previous inverted)(flat inverted) --- filter B, bin 2, night 210408(flat inverted) --- filter SG, bin 2, night 210419(flat inverted) --- filter SI, bin 2, night 210408(flat inverted) --- filter SR, bin 2, night 210407(flat inverted) --- filter V, bin 2, night 210417