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Filters

The filters currently available are listed in Table F.1, together with the measured passbands of the broad-band set convolved with chip response curves, the relative focus position for each filter (section 1.5.3) and detailed specifications of the filters.

There are two filter wheels, one of which is kept permanently loaded with the standard set of broad-band filters. The wheels and filters reside in the filter cupboard of the Optics Lab on the second floor. Get technical support or support-astronomer help if you wish to change filters or filter wheels at the prime focus; but if you have informed the island via your support astronomer of filter requirements, all should be in readiness for you.

On no account change filters in the broad-band wheel without informing island technical support.

The WHEEL command (section 3.2.4) is used to set up the filter wheel in software, so that abbreviated descriptions of the filters in the FILTER command (e.g. U(ltraviolet); 3.2.1 give correct filter settings. To set up a wheel with, say, narrow-band filters, or your own filters:

Adam:> WHEEL (and follow prompts),

or

Adam:> WHEEL < wheel-name> (if you know what you want)

Then to set the required filter position:

As a check:

Adam:> FILTSTATUS (yields verification)