Filters


Filter FWHM (Å) CWL (Å) Telescope Instrument Plot Data Comments
KP1517 76.36 6866.80 Nicholas U. Mayall 4-meter Telescope KOSMOS KP1517 KP1517 KOSMOS Approved KPNO 4in. Filter.
GG-400b 0.00 0.00 Nicholas U. Mayall 4-meter Telescope RC Spectrograph GG-400b GG-400b Sharp-Cut Filter. Cutoff filter: no transmission peak, FWHM is undefined.
U k1001 630.71 3552.00 Nicholas U. Mayall 4-meter Telescope Mosaic U k1001 U k1001 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.
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%.
O3 OIII N2 k1014 * Nicholas U. Mayall 4-meter Telescope Mosaic O3 OIII N2 k1014 * O3 OIII N2 k1014 * 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=5006A, FWHM=56A, PEAK TRANSMISSION=76%.
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.
918R 918R_v1 k1028 Nicholas U. Mayall 4-meter Telescope Mosaic 918R 918R_v1 k1028 918R 918R_v1 k1028 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) and the CTIO 4m (f/2.9). At the KPNO 4m f/3.1 the properties of this filter are: CWL=9140A, FWHM=81A, PEAK TRANSMISSION=84.7%.
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)
493 BATC k1055 ** Nicholas U. Mayall 4-meter Telescope Mosaic 493 BATC k1055 ** 493 BATC k1055 ** 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.
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.
o2 OII c6012 50.00 3727.00 Nicholas U. Mayall 4-meter Telescope Mosaic o2 OII c6012 o2 OII c6012 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.
Janos HK Band Filter Nicholas U. Mayall 4-meter Telescope Flamingos Janos HK Band Filter Janos HK Band Filter Cuton: 1.37 - Cutoff: 2.6
J1, Yale J1 160.60 1048.40 Nicholas U. Mayall 4-meter Telescope NEWFIRM Use with 2202
KS 313 315.00 2128.00 Nicholas U. Mayall 4-meter Telescope NEWFIRM Use with 3103. These filters have never been used in NEWFIRM.
BG38 2950.00 5010.00 Nicholas U. Mayall 4-meter Telescope KOSMOS BG38 BG38 Bandpass filter. For engineering purposes, not available to users.
GG-420 0.00 0.00 Nicholas U. Mayall 4-meter Telescope RC Spectrograph GG-420 GG-420 Sharp-Cut Filter. Cutoff filter: no transmission peak, FWHM is undefined.
U k1001 Nicholas U. Mayall 4-meter Telescope Mosaic U k1001 U k1001
M Washington k1007 1140.00 5100.00 Nicholas U. Mayall 4-meter Telescope Mosaic M Washington k1007 M Washington k1007 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 plot at the bottom of the page.
Ooff OIII+30nm k1015 242.69 5317.54 Nicholas U. Mayall 4-meter Telescope Mosaic Ooff OIII+30nm k1015 Ooff OIII+30nm k1015 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 redder. See the plot at the bottom of the page.
Bw NDWFS k1025 Nicholas U. Mayall 4-meter Telescope Mosaic Bw NDWFS k1025 Bw NDWFS k1025
gd DECam k1035 *** New! 1524.00 4744.90 Nicholas U. Mayall 4-meter Telescope Mosaic gd DECam k1035 *** New! gd DECam k1035 *** 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.
815 815_v2 k1046 Nicholas U. Mayall 4-meter Telescope Mosaic 815 815_v2 k1046 815 815_v2 k1046
493 BATC k1055 ** Nicholas U. Mayall 4-meter Telescope Mosaic 493 BATC k1055 ** 493 BATC k1055 **
848 BATC k1063 ** Nicholas U. Mayall 4-meter Telescope Mosaic 848 BATC k1063 ** 848 BATC k1063 **
s2 SII c6013 80.00 6725.00 Nicholas U. Mayall 4-meter Telescope Mosaic s2 SII c6013 s2 SII c6013 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.
James Rhoads Low-background J Filter Nicholas U. Mayall 4-meter Telescope Flamingos James Rhoads Low-background J Filter Cuton: 1.050 - Cutoff: 1.385
J1 blocker, Yale J1 blocker 321.00 1097.00 Nicholas U. Mayall 4-meter Telescope NEWFIRM Use with 2201
KS 318 312.00 2129.00 Nicholas U. Mayall 4-meter Telescope NEWFIRM Use with 3103
GG455 0.00 4565.00 Nicholas U. Mayall 4-meter Telescope KOSMOS GG455 GG455 KOSMOS dedicated blocker
GG-455 0.00 0.00 Nicholas U. Mayall 4-meter Telescope RC Spectrograph GG-455 GG-455 Sharp-Cut Filter. Cutoff filter: no transmission peak, FWHM is undefined.
U k1001 Nicholas U. Mayall 4-meter Telescope Mosaic U k1001
M Washington k1007 Nicholas U. Mayall 4-meter Telescope Mosaic M Washington k1007 M Washington k1007 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=5168A, FWHM=1126A, PEAK TRANSMISSION=86.5%.
Ooff OIII+30nm k1015 Nicholas U. Mayall 4-meter Telescope Mosaic Ooff OIII+30nm k1015 Ooff OIII+30nm k1015 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=5298.69A FWHM=240.20A PEAK TRANSMISSION=91.73%
Bw NDWFS k1025 Nicholas U. Mayall 4-meter Telescope Mosaic Bw NDWFS k1025 Bw NDWFS k1025 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) and the CTIO 4m (f/2.9). At the KPNO 4m f/3.1 the properties of this filter are: CWL=4091A, FWHM=1250A, PEAK TRANSMISSION=91.7%.
rd DECam k1036 *** New! 1426.90 6395.60 Nicholas U. Mayall 4-meter Telescope Mosaic rd DECam k1036 *** New! rd DECam k1036 *** 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.
815 815_v2 k1046 Nicholas U. Mayall 4-meter Telescope Mosaic 815 815_v2 k1046 A comparison of this filter with the older version of this filter (k1026):
527 BATC k1056 ** Nicholas U. Mayall 4-meter Telescope Mosaic 527 BATC k1056 ** 527 BATC k1056 ** 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.
918 BATC k1064 ** Nicholas U. Mayall 4-meter Telescope Mosaic 918 BATC k1064 ** 918 BATC k1064 ** 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.
o3 OIII c6014 50.00 4990.00 Nicholas U. Mayall 4-meter Telescope Mosaic o3 OIII c6014 o3 OIII c6014 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.
J2, Yale J2 152.80 1190.30 Nicholas U. Mayall 4-meter Telescope NEWFIRM Use with 2205
KXS 320.00 2150.00 Nicholas U. Mayall 4-meter Telescope NEWFIRM KXS
GG495 0.00 4950.00 Nicholas U. Mayall 4-meter Telescope KOSMOS GG495 GG495 KOSMOS dedicated blocker
GG-475 0.00 0.00 Nicholas U. Mayall 4-meter Telescope RC Spectrograph GG-475 GG-475 Sharp-Cut Filter. Cutoff filter: no transmission peak, FWHM is undefined.
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.
D51 DDO 51 k1008 162.90 5145.20 Nicholas U. Mayall 4-meter Telescope Mosaic D51 DDO 51 k1008 D51 DDO 51 k1008 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.
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.
815 815_v1 k1026 70.36 8152.10 Nicholas U. Mayall 4-meter Telescope Mosaic 815 815_v1 k1026 815 815_v1 k1026 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 (k1046) was purchased. See below for a comparison between the two filters.
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.
815 815_v2 k1046 Nicholas U. Mayall 4-meter Telescope Mosaic 815 815_v2 k1046 815 815_v2 k1046 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= 8109.85A FWHM= 68.62A PEAK TRANSMISSION= 81.42% at 8122A
527 BATC k1056 ** Nicholas U. Mayall 4-meter Telescope Mosaic 527 BATC k1056 ** 527 BATC k1056 **