CFHT Interference Filter Database Warnings for Use
HTML version created by Greg Barrick
Maintained by Greg Barrick
Last updated: 14 August 1998
Send comments to barrick@cfht.hawaii.edu.
- The transmission curves for all of the filters were measured at about
f/8 and 20 degrees Celsius. The beam speed should shift the central
wavelength redward by about 0.036%. The central wavelength will shift
by about 0.12 - 0.44 Angstroms per Celsius degree (0.004% per degree),
however. A means to measure the transmission of filters at operating
conditions (0 Celsius for visible and 77 K for IR) is on our project
list, but it will be some time before it is realized.
- As a reminder, the filters over 6 mm thick will not fit into FOCAM.
- FTS InSb dewars require two (2) identical filters to operate properly.
Just because a filter is listed under the FTS filter list does NOT mean that
it has a matching filter. This is not a problem with BEAR mode which requires
only one filter.
- Filters in the Laboratory filter list are not for general use and will
not be put into instruments for observering runs. These are for laboratory
use only.
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