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Order sorting filters

The standard ASCF (above slit colour filter) has 6 positions that correspond to

These are general order sorting filters or other discrimination. Figure 2.5 gives their wavelength dependent transmission. All filters are 2mm thick with selective antireflection coatings added.

A non-standard slide (ASCF #0) is available for users to request special setups. The slide can accomodate 5 standard-size filters (45mm by 60mm by 3mm) or 4 standard-size filters plus one 50mm diameter which requires a special mounting to insert it into the tray. Users may provide their own filters in advance for an observing session, to be mounted on this slide by local support.

The slide BSCF (below slit colour filter) can carry filters in positions 1 and 2, 0 is clear. If you use below slit filters, the collimator has to be moved to account for the change in the optical path length.

Wed Apr 6 22:56:39 BST 1994