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MOSAIC Filters

The Mosaic II imager, used at the Blanco 4-m prime focus, takes filters that are 146x146 mm and 12 mm (nominal) thick. A set of standardized filter names and IDs for both Mosaic I on the KPNO Mayall and Mosaic II on the CTIO Blanco have been developed to ensure proper application of astrometric solutions and real-time display processing (as well as future archive uniformity). These official names are listed in the Mosaic filter list web page.

Focus offsets are referred to the R filter, since this is the filter we use for taking focus frames each night when the Mosaic is installed in order to monitor telescope performance.
Note that the Sloan set (griz) and the Johnson-Cousins BVR (but not I) sets should be near-identical to those at KPNO.

Note: The central wavelength of narrow band filters (actually all filters, but it is very significant for narrow band filters) is shifted  approx. 15A to the BLUE in the f/2.87 beam of the Blanco 4m + PFADC corrector as compared to the transmission measured in parallel light. The central wavelengths quoated below are nominally for when the filters used at PF, with the approx. 15A shift included. Furthermore, the filter transmission curves presented below show the simulated filter tranmission curve for the Blanco 4m + PFADC f/2.87 beam.

Note: The Blanco prime focus corrector has poor response in the UV: 90% (4000A), 85% (3800A), 74% (3650A), 54% (3500A), 31% (3400A), 11% (3350A), 0% (3300A). These are calculations from the glass types and AR coating specifications, and the figures for 3300-3400A are rather uncertain. YOU STRONGLY ENCOURAGED TO USE THE u(SDSS) filter rather than the U filter. Neither of these filters, in combination with the CCDs and optical corrector, match the standard passbands perfectly. The U filter uses a (troublesome!) copper sulphate solution as red blocker, whereas the SDSS u filter is an interference filter.

 

Mosaic

Filter FWHM (Å) CWL (Å) Telescope Instrument Plot Data Comments
Us solid U k1044 Nicholas U. Mayall 4-meter Telescope Mosaic Us solid U k1044 Us solid U k1044
755 BATC k1061 ** Nicholas U. Mayall 4-meter Telescope Mosaic 755 BATC k1061 ** 755 BATC k1061 **
ha4 H-alpha+4nm k1010 Nicholas U. Mayall 4-meter Telescope Mosaic ha4 H-alpha+4nm k1010 ha4 H-alpha+4nm k1010 Below is a plot of the transmission of this filter when used at telescopes with differing focal ratios and central obscurations; the KPNO 4m (f/3.1), the CTIO 4m (f/2.9), and the WIYN 0.9m (f/7.9). At the KPNO 4m f/3.1 the properties of this filter are: CWL=6593A, FWHM=81A, PEAK TRANSMISSION=91.1%.
823 823_v1 k1027 70.61 8232.04 Nicholas U. Mayall 4-meter Telescope Mosaic 823 823_v1 k1027 823 823_v1 k1027 Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer. See the plot at the bottom of the page. Note: In December 2003 a replacement for this filter (k1047) was purchased. See below for a comparison of the two filters.
337 BATC k1051 ** Nicholas U. Mayall 4-meter Telescope Mosaic 337 BATC k1051 ** 337 BATC k1051 ** Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer.
V Harris c6026 940.00 5370.00 Nicholas U. Mayall 4-meter Telescope Mosaic V Harris c6026 V Harris c6026 Note: The central wavelength of CTIO Mosaic narrow band filters (actually all filters, but is very significant for narrow band filters) is shifted ~15A to the BLUE in the f/2.87 beam of the Blanco 4m + PFADC corrector as compared to the transmission measured in parallel light. The central wavelength quoted below is nominally for when the filter is used at PF, with the ~15A shift included. Furthermore, the filter transmission curve presented below shows the simulated filter transmission curve for the Blanco 4m + PFADC f/2.87 beam.
B Harris k1002 993.88 4381.00 Nicholas U. Mayall 4-meter Telescope Mosaic B Harris k1002 B Harris k1002 Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer.
wh Bk-7 k1016 6800.00 5600.00 Nicholas U. Mayall 4-meter Telescope Mosaic wh Bk-7 k1016 wh Bk-7 k1016 Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer.
zd DECam k1038 *** New! 1467.00 9280.00 Nicholas U. Mayall 4-meter Telescope Mosaic zd DECam k1038 *** New! zd DECam k1038 *** New! Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer.
527 BATC k1056 ** Nicholas U. Mayall 4-meter Telescope Mosaic 527 BATC k1056 ** 527 BATC k1056 **
wh Bk-7 c6016 5000.00 6500.00 Nicholas U. Mayall 4-meter Telescope Mosaic
I Nearly-Mould k1005 Nicholas U. Mayall 4-meter Telescope Mosaic I Nearly-Mould k1005
wrc4 WR CIV k1024 41.79 5828.71 Nicholas U. Mayall 4-meter Telescope Mosaic wrc4 WR CIV k1024 wrc4 WR CIV k1024 Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer. See the plot at the bottom of the page.
Ud Dey custom U k1045 329.76 3485.23 Nicholas U. Mayall 4-meter Telescope Mosaic Ud Dey custom U k1045 Ud Dey custom U k1045 Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer.
802 BATC k1062 ** Nicholas U. Mayall 4-meter Telescope Mosaic 802 BATC k1062 ** 802 BATC k1062 ** Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer.
ha8 H-alpha+8nm k1011 81.33 6654.19 Nicholas U. Mayall 4-meter Telescope Mosaic ha8 H-alpha+8nm k1011 ha8 H-alpha+8nm k1011 Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer See the plot at the bottom of the page.
823 823_v1 k1027 Nicholas U. Mayall 4-meter Telescope Mosaic 823 823_v1 k1027 823 823_v1 k1027
337 BATC k1051 ** Nicholas U. Mayall 4-meter Telescope Mosaic 337 BATC k1051 ** 337 BATC k1051 **
R Harris c6004 1510.00 6440.00 Nicholas U. Mayall 4-meter Telescope Mosaic R Harris c6004 R Harris c6004 Note: The central wavelength of CTIO Mosaic narrow band filters (actually all filters, but is very significant for narrow band filters) is shifted ~15A to the BLUE in the f/2.87 beam of the Blanco 4m + PFADC corrector as compared to the transmission measured in parallel light. The central wavelength quoted below is nominally for when the filter is used at PF, with the ~15A shift included. Furthermore, the filter transmission curve presented below shows the simulated filter transmission curve for the Blanco 4m + PFADC f/2.87 beam.
B Harris k1002 Nicholas U. Mayall 4-meter Telescope Mosaic B Harris k1002 B Harris k1002
g SDSS k1017 1395.73 4750.58 Nicholas U. Mayall 4-meter Telescope Mosaic g SDSS k1017 g SDSS k1017 Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer.
VR k1039 *** New! 2216.00 5940.00 Nicholas U. Mayall 4-meter Telescope Mosaic VR k1039 *** New! VR k1039 *** New! NOTE: This filter is a replacement for k1040. Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer.
579 BATC k1057 ** Nicholas U. Mayall 4-meter Telescope Mosaic 579 BATC k1057 ** 579 BATC k1057 ** Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer.
g SDSS c6017 1537.00 4813.00 Nicholas U. Mayall 4-meter Telescope Mosaic g SDSS c6017 g SDSS c6017 Note: The central wavelength of CTIO Mosaic narrow band filters (actually all filters, but is very significant for narrow band filters) is shifted ~15A to the BLUE in the f/2.87 beam of the Blanco 4m + PFADC corrector as compared to the transmission measured in parallel light. The central wavelength quoted below is nominally for when the filter is used at PF, with the ~15A shift included. Furthermore, the filter transmission curve presented below shows the simulated filter transmission curve for the Blanco 4m + PFADC f/2.87 beam.
C Washington k1006 1034.00 3860.00 Nicholas U. Mayall 4-meter Telescope Mosaic C Washington k1006 C Washington k1006 Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer. See the plot at the bottom of the page.
wrc4 WR CIV k1024 Nicholas U. Mayall 4-meter Telescope Mosaic wrc4 WR CIV k1024 wrc4 WR CIV k1024 Below is a plot of this filter as simulated in different f/ratio beams. At the KPNO 4m f/3.1 the properties of this filter are: CWL=5819A FWHM=42.17A PEAK TRANSMISSION=71.36%
Ud Dey custom U k1045 Nicholas U. Mayall 4-meter Telescope Mosaic Ud Dey custom U k1045 Ud Dey custom U k1045
802 BATC k1062 ** Nicholas U. Mayall 4-meter Telescope Mosaic 802 BATC k1062 ** 802 BATC k1062 **
ha8 H-alpha+8nm k1011 Nicholas U. Mayall 4-meter Telescope Mosaic ha8 H-alpha+8nm k1011 ha8 H-alpha+8nm k1011 Below is a plot of the transmission of this filter when used at telescopes with differing focal ratios and central obscurations; the KPNO 4m (f/3.1), the CTIO 4m (f/2.9), and the WIYN 0.9m (f/7.9). At the KPNO 4m f/3.1 the properties of this filter are: CWL=6634A, FWHM=81A, PEAK TRANSMISSION=89.2%.
823 823_v1 k1027 Nicholas U. Mayall 4-meter Telescope Mosaic 823 823_v1 k1027 A comparison of this filter with the newer version (k1047):
390 BATC k1052 ** Nicholas U. Mayall 4-meter Telescope Mosaic 390 BATC k1052 ** 390 BATC k1052 ** Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer.
I c6028 1500.00 8050.00 Nicholas U. Mayall 4-meter Telescope Mosaic I c6028 I c6028 Note: The central wavelength of CTIO Mosaic narrow band filters (actually all filters, but is very significant for narrow band filters) is shifted ~15A to the BLUE in the f/2.87 beam of the Blanco 4m + PFADC corrector as compared to the transmission measured in parallel light. The central wavelength quoted below is nominally for when the filter is used at PF, with the ~15A shift included. Furthermore, the filter transmission curve presented below shows the simulated filter transmission curve for the Blanco 4m + PFADC f/2.87 beam.
B Harris k1002 Nicholas U. Mayall 4-meter Telescope Mosaic B Harris k1002
r SDSS k1018 1475.17 6292.28 Nicholas U. Mayall 4-meter Telescope Mosaic r SDSS k1018 r SDSS k1018 Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer.
VR Bernstein k1040 *** Retired! 2119.56 5944.95 Nicholas U. Mayall 4-meter Telescope Mosaic VR Bernstein k1040 *** Retired! VR Bernstein k1040 *** Retired! NOTE: This filter was damaged in June 2011 and is retired. Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer. See the plot at the bottom of the page.
579 BATC k1057 ** Nicholas U. Mayall 4-meter Telescope Mosaic 579 BATC k1057 ** 579 BATC k1057 **
r SDSS c6018 1468.00 6287.00 Nicholas U. Mayall 4-meter Telescope Mosaic r SDSS c6018 r SDSS c6018 Note: The central wavelength of CTIO Mosaic narrow band filters (actually all filters, but is very significant for narrow band filters) is shifted ~15A to the BLUE in the f/2.87 beam of the Blanco 4m + PFADC corrector as compared to the transmission measured in parallel light. The central wavelength quoted below is nominally for when the filter is used at PF, with the ~15A shift included. Furthermore, the filter transmission curve presented below shows the simulated filter transmission curve for the Blanco 4m + PFADC f/2.87 beam.
C Washington k1006 Nicholas U. Mayall 4-meter Telescope Mosaic C Washington k1006 C Washington k1006 Below is a plot of the transmission of this filter when used at telescopes with differing focal ratios and central obscurations; the KPNO 4m (f/3.1), the CTIO 4m (f/2.9), and the WIYN 0.9m (f/7.9). At the KPNO 4m f/3.1 the properties of this filter are: CWL=3892A, FWHM=1030A, PEAK TRANSMISSION=77.4%.
Bw NDWFS k1025 1275.21 4110.78 Nicholas U. Mayall 4-meter Telescope Mosaic Bw NDWFS k1025 Bw NDWFS k1025 Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer. See the plot at the bottom of the page. Note: This filter was called the NDWFS UB filter in 1997-1998.
815 815_v2 k1046 68.53 8152.64 Nicholas U. Mayall 4-meter Telescope Mosaic 815 815_v2 k1046 815 815_v2 k1046 Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer. See the plot at the bottom of the page. Note: This is a replacement for the old Rhoads 815 filter (k1026)
848 BATC k1063 ** Nicholas U. Mayall 4-meter Telescope Mosaic 848 BATC k1063 ** 848 BATC k1063 ** Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer.
ha12 H-alpha+12nm k1012 82.95 6698.53 Nicholas U. Mayall 4-meter Telescope Mosaic ha12 H-alpha+12nm k1012 ha12 H-alpha+12nm k1012 Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer. See the plot at the bottom of the page.
823 823_v1 k1027 Nicholas U. Mayall 4-meter Telescope Mosaic 823 823_v1 k1027
390 BATC k1052 ** Nicholas U. Mayall 4-meter Telescope Mosaic 390 BATC k1052 ** 390 BATC k1052 **
C Washington c6029 1075.00 3850.00 Nicholas U. Mayall 4-meter Telescope Mosaic
V Harris k1003 948.66 5386.76 Nicholas U. Mayall 4-meter Telescope Mosaic V Harris k1003 V Harris k1003 Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer.
i SDSS k1019 1539.89 7726.28 Nicholas U. Mayall 4-meter Telescope Mosaic i SDSS k1019 i SDSS k1019 Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer.
VR Bernstein k1040 *** Retired! Nicholas U. Mayall 4-meter Telescope Mosaic VR Bernstein k1040 *** Retired! VR Bernstein k1040 *** Retired! Below is a plot of the transmission of this filter when used at telescopes with differing focal ratios and central obscurations; the KPNO 4m (f/3.1), the CTIO 4m (f/2.9), and the WIYN 0.9m (f/7.9). At the KPNO 4m f/3.1 the properties of this filter are: CWL=5934A, FWHM=2079A, PEAK TRANSMISSION=95.3%.
607 BATC k1058 ** Nicholas U. Mayall 4-meter Telescope Mosaic 607 BATC k1058 ** 607 BATC k1058 ** Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer.
i SDSS c6019 1548.00 7732.00 Nicholas U. Mayall 4-meter Telescope Mosaic i SDSS c6019 i SDSS c6019 Note: The central wavelength of CTIO Mosaic narrow band filters (actually all filters, but is very significant for narrow band filters) is shifted ~15A to the BLUE in the f/2.87 beam of the Blanco 4m + PFADC corrector as compared to the transmission measured in parallel light. The central wavelength quoted below is nominally for when the filter is used at PF, with the ~15A shift included. Furthermore, the filter transmission curve presented below shows the simulated filter transmission curve for the Blanco 4m + PFADC f/2.87 beam.
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Last updated: 2009 Dec 9, ARW

 

Staff Contacts:
Sean Points: spointsATctio.noao.edu
Alistair Walker: awalkerATctio.noao.edu

Updated on June 5, 2021, 8:00 pm