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Specification of the narrow band filters

Unless otherwise specified the effects of an f4.5 converging beam of light has been taken into account and the central wavelength duly reddened. A correction of +2 Angstroms has also been made to correct the central wavelength for operation at +10 degrees Celsius on the assumption that the filters will be made, tested and specified at +20 degrees Celsius.

In all cases the thickness of the filter including blocking filters should not exceed 9mm and should be the same for all filters wherever possible. Blocking in all cases should be 3000-12000 Angstroms and the tolerance on the central wavelength should be 3 Angstroms. The tolerance on the dimensions of each filter should be 0.5mm. Filters should be free from pinholes greater than 0.03mm diameter in the central 25mm diameter circle and free from pinholes greater than 0.1mm diameter elsewhere.

Table: Summary of 50 mm filters for CCD imaging

Table: Summary of 50 mm filters for CCD imaging (continued)

Tue Aug 15 16:42:46 BST 1995