... It has a removable ADC and a curve dewar window. ... Table 3-2 VST optical data for camera, ADC , filter and dewar window in, B, V, R, I bands Element L1 L2 Filter Dewar window OPTICAL DATA FOR TWO LENSES CONFIGURATION R1 R2 Material Diameter Thickness 794.33 mm 1044.1 mm Silica 430.3 mm 58.45mm 417.6mm -1453.8 8912.5mm Silica 384 ... 375.4 mm 15 mm 375 mm Infinity Infinity Silica 372.8 mm 20 mm 372.5 mm Air thickness 214.65mm 149.1 mm 50 mm 25 mm Table 3-3 VST optical data for ...