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Filters

Two filter slides, situated below the autoguider assembly, in the on axis light path, provide colour and ND filtering. Each slide carries five filters in cells, and the cells all carry discrete bar coding for filter identification. The filter cell carrier may be removed and alternative cells fitted. The filters have a maximum diameter of 85 mm. The name of the filter mounted in each position may be determined using a barcode reader. The neutral density filters mounted are ND0.3, ND0.9, ND1.2, ND1.8, ND3.0 and the colour filters mounted are UG1, BG38, GG495, RG630, WG320.