CFHT Interference Filter Database Recent Changes

HTML version created by Greg Barrick

Maintained by Greg Barrick

Last updated: 7 June 2005

Send comments to

7 June 2005

The acsii data has been added to the Wircam filter database and is available by clicking on "data".

29 December 2004

The Wircam 110 mm round interference filters have been added to the Web database and the filter codes changed slightly. Since the photographic plate filters are no longer used, the 8000 series has been converted over to the Wircam numbers. At this time, the ascii data and curves are not available, I hope to have them added within a few weeks.

18 March 2003

The database has been updated to reflect a number of changes. Since OASIS and its filters (with the exception of MR0) are no longer here at CFHT, the 9000 series has now been designated as Megaprime filters. The Megaprime filters have been added, along with a number of photographic plate filters in the 8000 series. Since I do not have a good way yet of including temperature and humidity data into the Megaprime filter data, I will list the values here for now.

9301 scanned at 44% RH and 68.5 degrees F.

9401 scanned at 43% RH and 68.7 degrees F.

9601 scanned at 46% RH and 68 degrees F.

9801 scanned at 50% RH and 67.8 degrees F.

9701 scanned at 54% RH and 66 degrees F.

19 December 2001

The database has been updated to include a link to the ASCII data that makes up the transmission curve. This data is available by clicking on "data" under the filter number.

01 November 2001

The database has been updated with three new 12K filters, three new MOS filters and six KIR filters on loan from Obs. de Paris.

We are now up to 394 filters in the database!

14 December 1999

The final CFHT-IR and KIR filters have finally arrived. They are added to the database along with a few other IR filters and two new 50.8x50.8 mm square U filters.

We are now up to 379 filters in the database!

12 August 1999

A new Gecko filter has been added to the database. This filter is a replacement for the old Sodium line filter.

We are now up to 362 filters in the database!

5 May 1999

Eight new filters have been added to the database including the new CFH12k B and H-alpha on filters.

We are now up to 361 filters in the database!

31 December 1998

CFH12k filters are now in the database. The transmission curve shown for each filter is the curve taken at the center of the filter. Scans toward the edge of the filters show significant differences. A way to display all available data on the 12k filters will be implemented soon.

We are now up to 353 filters in the database!

6 November 1998

All of the Oasis filters have been added to the filter database. These are 1 inch (25.4 mm) round filters and most of them are owned by the Observatoire de Lyon. These filters have filter numbers that begin with 9. This number will be used with all 25.4 mm round visible filters.

We are now up to 349 filters in the database!

14 August 1998

Two new categories have been added: CFHT-IR and Laboratory. CFHT-IR filters are 25.4 mm round IR filter bought for the CFHT-IR camera. Thes filters only show up under this instrument and are no longer listed under Redeye and FTS. The Laboratory filters are a set of filters which, due mainly to reasons of quality, are no longer listed for use by observers, but may be used by CFHT personnel ONLY for instrument testing.

We are now up to 334 filters in the database!

8 May 1998

The transmission curves for the UH8k filters are now available. They are only under the instrument list and are not in the regular filter database. They have not been given CFH number and are referred to by the filter name.

Most IR filters (for Redeye, FTS, and KIR) have been scanned and labeled with a CFHT number. They are also now listed in the normal filter database. For convenience the links to the filter curves in the Redeye and FTS manuals will be kept on the filter database page. The curves attached to the filter list were scanned warm. The leading number for the filter numbers is 5 for 25.4 mm round filters (Redeye and FTS) and 6 for 12.7 mm round filters (KIR).

A category has been added to list the CFH 12k filters, but no filters are currently in the database. These filters are 165 x 250 mm rectangular. They will be grouped with the UH8k and MOCAM filters in the database list.

We are now up to 301 filters in the database.

Return to Filter Database Homepage