CFHT Information Bulletin Number 37, Semester 97II

CFH12k Filters

Dennis Crabtree, CFHT (

The large filters required for CFH12k require a lead time of 4-6 months in their acquisition. This means that we cannot always wait until observing time is granted before acquiring necessary filters. CFHT feels that we should have filters which we expect to be requested in house to ensure they will be available for scheduled runs. We have already ordered broadband B, V, R, and I filters. We did an e-mail survey asking the communities which other filters they would like to see available for use with CFH12k.

Given the size of the filters (165 mm x 250 mm) required for CFH12k there are some limitations. We have yet to find a manufacturer who will construct a filter this size with a bandpass < 50 Å. Also, filters of this size are fairly expensive so we will have to be selective about which ones are ordered.

We received more than 10 responses to the e-mail request for suggested filters, in addition to B, V, R, and I which have been ordered, for CFH12K. Filters that were suggested included:

CFHT Information Bulletin Number 37, Semester 97II
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