Nordic Optical Telescope

All available optical filters

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Min FWHM Max FWHM

Note, for cut-on, cut-off and multi pass band (GG385 UG1) filters the FWHM has been set to 0. The Cenwave indicates the blue peak of the UG1 and GG375 filters and the cut wavelength for the rest of these filters.

Sort by clicking the column title, e.g. click on Cenwave to order the filters from blue to red

ID Name Thick.
(mm) Size
(mm) Shape Cenwave
(nm) FWHM
(nm) Tmax
(%) Throughput cosmetics comment ID
301 ING065 png, ascii 301
302 ING066 png, ascii 302
1 U_Bes 366_52 60 Round 366 52 52 png, ascii HiRAC special, with rlb 1
2 B_Bes 428_105 60 Round 428 105 62 png, ascii HiRAC special 2
3 V_Bes 535_76 8.6 60 Round 535 76 77 png, ascii HiRAC special 3
4 R_Bes 631_121 8.6 60 Round 631 121 71 png, ascii HiRAC special 4
5 i_int 810_125 9.6 60 Round 810 125 87 png, ascii HiRAC special 5
6 U_Bes 363_56 5 60 Round 363 56 62 png, ascii 2 small stains on coating. UD StanCam fixed set-up; Bessell U with rlb;focus reference R-filter 6
7 U_Bes 362_60 60 Round 362 60 60 png, ascii C, UD ALFOSC fixed set-up. Bessell U with rlb 7
8 B_Bes 429_106 5.1 60 Round 429 106 61 png, ascii Coating stained both sides StanCam fixed set-up; focus reference R-filter 8
9 V_Bes 543_103 5 60 Round 543 103 82 png, ascii C, UD StanCam fixed set-up; focus reference R-filter 9
10 R_Bes 641_148 5 60 Round 641 148 79 png, ascii C, UD Bessell R; StanCam fixed set-up; focus refernce R-filter 10
11 I_Bes 728_LP 5 60 Round 728 96 png, ascii Bessell I, cut-on 11
12 i_int 797_157 60 Round 797 157 91 png, ascii ALFOSC fixed set-up; interference i 12
13 i_int 793_170 9 60 Round 793 170 80 png, ascii C, UD StanCam fixed set-up; interference i; focus reference R filter 13
14 r_Gun 680_102 5.4 60 Round 680 102 86 png, ascii Two chips of about 7mm at edge interference r, Gunn r 14
15 u_Str 351_34 5.8 60 Round 351 34 52 png, ascii C, UD Stromgren u 15
16 v_Str 411_18 4.8 60 Round 411 18 66 png, ascii Coating slightly fogged. UD Stromgren v 16
17 b_Str 467_18 4.8 60 Round 467 18 89 png, ascii C, UD Stromgren b 17
18 y_Str 547_22 4.8 60 Round 547 22 86 png, ascii Coating slightly fogged. UD Stromgren y 18
19 Hbet 485_4 5.8 60 Round 485.4 4 70 png, ascii Hbeta narrow 19
20 Hbet 485_13 5.7 60 Round 485.4 13.3 81 png, ascii C, UD. Rim transparent Hbeta wide 20
21 Halp 656_3 6.2 60 Round 656.4 3.3 66 png, ascii H alpha narrow 21
22 Halp 658_18 6.3 60 Round 657.7 18 77 png, ascii H alpha wide, stiff in FASU holder 22
23 [SII] 403_3 10.1 60 Round 403.3 3.5 46 png, ascii C, UD. Rim transparent Miller blue 23
24 407_3 10 60 Round 406.6 3 48 png, ascii C, UD. Rim transparent Miller blue 24
25 [SII] 1020_10 10 60 Round 1020 10 85 png, ascii C, UD. Rim transparent Miller IR 25
26 1033_10 10.1 60 Round 1033 10 87 png, ascii C, UD. Rim transparent Miller IR 26
71 BG25-O 390_MP 100 Round 393 84 png, ascii C, UD standard, FWHM_blue 125 nm 71
72 UG1 360_MP 100 Round 360 67 png, ascii C, UD standard, FWHM_blue=63nm 72
73 GG385 380_LP 2 100 Round 380 90 png, ascii C, UD, use brass spacer ring cut-on 73
74 B_Bes 440_100 60 Round 440 100 68 png, ascii C, UD ALFOSC fixed set-up 74
75 V_Bes 530_80 60 Round 530 80 85 png, ascii C, UD ALFOSC fixed set-up 75
76 R_Bes 650_130 60 Round 650 130 81 png, ascii C, UD ALFOSC fixed set-up 76
77 662_4 4.9 60 Round 662.1 3.9 66 png, ascii C, UD. Rim transparent Halpha red continuum, ghosts , variable, up to 3% 77
78 [NII] 658_4 4.7 60 Round 658.3 3.6 74 png, ascii Clean, coating spotty. Rim transparent [NII] line 78
79 HeII 469_3 4.8 60 Round 468.7 3.5 69 png, ascii Coating slightly fogged. UD HeII line 79
80 NaD 589_5 13 Round 589.3 5 89 png, ascii C, UD NaD line, SOFIN 80
81 [SIII] 953_3 4.7 60 Round 953.1 3 62 png, ascii C, UD [SIII] line 81
82 u'_SDSS 350_65 5 59.9 Round 350 65 79 png, ascii C; UD spare SDSS set 82
83 g'_SDSS 480_145 5 60 Round 480 145 92 png, ascii C, UD, does not fit in ALFOSC StanCam fixed set-up; does not fit in ALFOSC;focus reference R filter 83
84 r'_SDSS 625_140 5 60.2 Round 625 140 94 png, ascii Clean, small blemish on coating, does not fit in ALFOSC spare SDSS set; does not fit in ALFOSC 84
85 i'_SDSS 770_160 5.1 60.15 Round 770 160 95 png, ascii C, UD ; does not fit in ALFOSC spare SDSS set; does not fit in ALFOSC 85
86 z'_SDSS 840_LP 5 60 Round 840 92 png, ascii C, UD StanCam fixed set-up; cut-on;focus reference R-filter 86
87 [OI] 630_3 5.4 60 Round 630 3 80 png, ascii C, UD [OI] line 87
88 [OII] 372_3 5.1 60 Round 372.8 3.2 27 png, ascii C, UD; has two big finger prints [OII] line 88
89 [NII] 575_3 4.7 60 Round 575.5 3 78 png, ascii C, UD. Rim transparent [NII] line 89
90 [OIII] 501_3 4.7 60 Round 500.7 3 82 png, ascii C, UD. Rim transparent [OIII] line 90
91 [SII] 673_1 5.1 60 Round 673.1 1 71 png, ascii C, UD. Rim transparent [SII] line 91
92 550_275 60 Round 550 275 92 png, ascii C, UD Sky contrast, similar to Gaia G BP-filter 92
97 357_2 8.8 60 Round 356.7 2 38 png, ascii C, UD redshifted Lyman alpha; J.Fynbo's filter 97
98 358_2 9 60 Round 357.8 2.5 48 png, ascii C; UD redshifted Lyman alpha; J.Fynbo's filter 98
99 369_4 7.2 60 Round 369.4 4 61 png, ascii C, UD, flatfield not flat redshifted Lyman alpha; J.Fynbo's filter 99
100 GG420 416_LP 3 60 Round 416 94 png, ascii C, UD cut-on 100
101 GG475 480_LP 3 60 Round 480 95 png, ascii C, UD cut-on, missing not available 101
102 OG515 518_LP 3 60 Round 518 92 png, ascii C, UD cut-on 102
103 OG575 566_LP 3.1 60 Round 566 91 png, ascii C, UD cut-on 103
104 U_Bes 361_62 5.3 100 Round 361 62 66 png, ascii C, UD Bessell U 104
105 B_Bes 428_108 5.1 100 Round 428 108 73 png, ascii C, UD Bessell B 105
106 V_Bes 536_89 5 100 Round 536 89 81 png, ascii C, UD Bessell V 106
107 R_Bes 646_124 5.2 100 Round 646 124 73 png, ascii C, UD Bessell R 107
108 I_int 817_163 5 100 Round 817 163 97 png, ascii C, UD interference i 108
109 u'_SDSS 353_55 5 100 Round 353 55 74 png, ascii C; UD FASU standard set-up 109
110 r'_SDSS 618_148 5.1 100 Round 618 148 90 png, ascii C; UD FASU standard set-up 110
111 i'_SDSS 771_171 5 100 Round 771 171 91 png, ascii C, UD FASU standard set-up 111
112 z'_SDSS 832_LP 5 100 Round 832 97 png, ascii C, UD FASU standard set-up, cut-on 112
114 u_Str 347_38 8.4 90 Round 347 38 55 png, ascii C; UD u Stromgren; IJAF/CUO filter: please contact staff 114
115 v_Str 412_18 4 90 Round 412 18 58 png, ascii C, UD v Stromgren; IJAF/CUO filter: please contact staff 115
116 b_Str 468_19 6 90 Round 468 19 66 png, ascii C, UD b Stromgren; IJAF/CUO filter: please contact staff 116
117 y_Str 547_21 6.5 90 Round 547 21 58 png, ascii C, UD y Stromgren; IJAF/CUO filter: please contact staff 117
118 Hb_Str 485_4 6 90 Round 485.3 3.7 51 png, ascii C, UD H-beta narrow Stromgren; IJAF/CUO filter: please contact staff 118
119 Hb_Str 487_14 6.6 90 Round 486.8 14.3 58 png, ascii C, UD H-beta wide Stromgren; IJAF/CUO filter: please contact staff 119
120 g'_SDSS 480_145 5.2 100 Round 480 145 92 png, ascii C, UD FASU standard set-up 120
121 406_6 8 100 Round 405.8 5.8 64 png, ascii C, UD Univ of Iceland filter: please contact staff 121
122 363_6 8 100 Round 362.7 5.8 51 png, ascii C, UD Univ. of Iceland filter: please contact staff 122
123 [SII] 672_5 7 60 Round 671.6 5 82 png, ascii C; UD Univ. of Aarhus: please contact staff 123
125 633_26 7.4 100 Round 633 26 91 png, ascii cosmetic Halpha_continuum; G. Ostlin's filter : please contact staff 125
129 489_5 6.35 60 Round 489.5 5 84 png, ascii C, UD H_beta redshifted; G. Ostlin's filter : please contact staff 129
132 463_248 1.9 60 round 463 248 92.5 png, ascii C,UD red cutoff filter 132
133 401_7 8.1 100 Round 401.3 6.4 72.5 png, ascii C, UD G.Ostlin's filter 133
134 391_7 7.6 100 Round 391.7 6.3 76 png, ascii C, UD G.Ostlin's filter 134
135 458_66 8 100 Round 458 66 90 png, ascii C, UD G.Ostlin's filter 135
136 397_6 6.8 100 Round 396.5 6.3 85 png, ascii C, UD G.Ostlin's filter 136
137 410_7 6.9 100 Round 410 7.2 76 png, ascii C, UD G.Ostlin's filter 137
27 B_Bes 432_107 7 51 Square 432.4 106.6 53 png, ascii B filter 27
28 V 539_71 5.7 51 Square 539 71 60 png, ascii coating slightly fogged V-like filter 28
29 Halp 656_16 5.6 51 Square 656 11.3 62 png, ascii H wide, edge bad; StanCam fixed set-up;focus reference R filter 29
30 [OII] 373_5 4.6 51 Square 372.6 5.1 25 png, ascii C,UD [OII] line 30
31 [NeIII] 387_4 6.2 51 Square 387.1 4.2 34 png, ascii C,UD [NeIII] line 31
32 Hdel 410_4 6.2 51 Square 410.2 4.2 45 png, ascii C, UD H(delta) line 32
33 Hgam 434_3 6.2 51 Square 434.5 2.9 48 png, ascii C,UD H(gamma) line 33
34 HeI 448_6 6.2 51 Square 447.6 5.6 45 png, ascii C, UD. Rim transparent HeI line 34
35 HeII 470_6 6.2 51 Square 469.6 5.7 60 png, ascii C, UD. Rim transparent HeII line 35
36 b_Str 472_20 6.2 51 Square 472 19.8 74 png, ascii C, UD Stromgren b 36
37 Hbet 487_5 6.2 51 Square 487.3 4.5 58 png, ascii C, UD. Rim transparent Hbeta 37
38 Hbet 489_10 6 51 Square 488.9 10.2 74 png, ascii C, UD, chip at corner Hbeta wide 38
39 Hbet 487_4 6.1 51 Square 487.4 3.9 57 png, ascii C, UD. Coating fogged at edge Hbeta narrow 39
40 [OIII] 501_4 6.2 51 Square 501 4.3 56 png, ascii C, UD [OIII] line 40
41 506_5 6.2 51 Square 506.1 4.9 69 png, ascii C, UD. Coating slightly spotty [OIII]rs 5nm 41
42 511_5 6.2 51 Square 511.1 4.9 59 png, ascii C, UD [OIII]rs 10nm 42
43 515.9_4 6.1 51 Square 515.9 4.3 56 png, ascii Clean, small chip in centre [OIII]rs 15nm 43
44 y_Str 552_18 6.1 51 Square 551.6 18.4 75 png, ascii C, UD. Rim transparent: use in StanCam only Stromgren y 44
45 HeI 588_6 6.2 51 Square 587.9 5.6 70 png, ascii Clean. Small chip at edge. Rim transparent HeI line 45
46 Eu 619_2 6.2 51 Square 618.8 2.5 49 png, ascii C, UD. Eu line, Ring mounted 46
47 [OI] 631_4 6.3 51 Square 630.8 4.5 77 png, ascii Clean, small scratch near edge [OI] line 47
48 635_4 6.1 51 Square 635.3 4.5 62 png, ascii C, UD [OI] rs 5nm 48
49 661_5 6.3 51 Square 661 5 76 png, ascii C; UD H rs 5nm 49
50 665_5 6.2 51 Square 665.3 5.5 80 png, ascii Clean, 10mm chip off edge H rs 10nm 50
51 670_4 6.3 51 Square 670.3 4.5 76 png, ascii C, UD H rs 15nm 51
52 [SII] 672_6 6.1 51 Square 672.5 6 71 png, ascii C, UD [SII] line 52
53 674_5 6.1 51 Square 674.5 5 74 png, ascii C, UD, chip at corner H rs 20nm 53
54 679_4 6.3 51 Square 678.8 4.5 73 png, ascii C, UD H rs 25nm 54
55 684_5 6.2 51 Square 684 5 70 png, ascii Worn coating H rs 30nm 55
56 688_6 6.2 51 Square 688.3 6.5 77 png, ascii C, UD H rs 35nm 56
57 692_5 6.2 51 Square 692.5 5.5 72 png, ascii C, UD H rs 40nm 57
58 696_5 6.2 51 Square 696.5 5 71 png, ascii Clean, some minute scratches H rs 45nm 58
59 HeI 727_2 6.2 51 Square 727.3 2.5 59 png, ascii C, UD special 59
60 751_5 6.1 51 Square 750.8 5.5 79 png, ascii C, UD special 60
61 892_5 6.1 51 Square 892.4 5.3 58 png, ascii C, UD special 61
62 948_5 6 51 Square 948 5 51 png, ascii C, UD special 62
63 v_Str 412_19 6 51 Square 411.7 18.8 62 png, ascii Clean, one minute chip on edge Stromgren v 63
64 Halp 656_5 6.1 51 Square 656.2 4.6 68 png, ascii Clean, large chip and stress mark Halpha 64
65 504_4 9.2 75 Square 504.5 3.7 58 png, ascii C, UD [OIII] rs 4nm 65
66 510_4 9.9 75 Square 510.5 3.7 55 png, ascii C, UD [OIII] rs 10 nm 66
67 521_10 9.2 75 Square 521.4 10.5 77 png, ascii Small spots on coating, UD [OIII] rs 20 nm 67
68 664_4 9.6 75 Square 664 4 66 png, ascii C, UD Hal rs 8 nm 68
69 670_3 9.9 75 Square 670 3 50 png, ascii C, UD Hal rs 15 nm 69
70 667_5 9.8 75 Square 667 5 72 png, ascii FILTER BROKEN Hal rs 11 nm ; FILTER BROKEN 70
93 GG375 375_LP 4 51 Square 375 88 png, ascii C, UD, corner chipped cut-on 93
94 WG345 356_LP 4 51 Square 356 88 png, ascii C, UD cut-on 94
95 674_LP 3.1 51 Square 674 91 png, ascii C; UD cut-on 95
96 776_LP 3 51 Square 776 88 png, ascii C, UD cut-on 96
113 494_5 5.9 51 Square 494.2 5.1 86 png, ascii C, UD G. Ostlin's filter 113
124 Sort13 554_166 5.2 51 Square 554 166 91 png, ascii cosmetic Order sorter for grism #13 124
126 WG280 280_LP 51 Square 280 png, ascii C, corner cracked cut-on, clear filter in STANCAM for FIES 126
127 515.6_4 8 75 Square 515.6 4 png, ascii C, UD Univ. of Aarhus: please contact staff 127
128 551_4 8 75 Square 550.7 4 png, ascii C, UD Univ. of Aarhus: please contact staff 128
130 381_8 8 75 Square 381.2 8 38 png, ascii C, UD 130
131 410_6 8 75 Square 410.2 6 53 png, ascii C,UD 131
138 Halp_656_3_OSN 5 50 Square 656.3 1 84 png, ascii C, UD IAA/OSN filter #H01: Please contact staff 138
139 [NII]_658_4_OSN 5 50 Square 658.4 1 77 png, ascii C, UD IAA/OSN filter #E16: Please contact staff 139
140 [OIII]_500_7_OSN 7 50 Square 500.7 5 70 png, ascii C, UD IAA/OSN filter #E10: Please contact staff 140
141 [HeII]_469_1_OSN 7 50 Square 469.1 5 57 png, ascii C, UD IAA/OSN filter #E07: Please contact staff 141
142 [OII]_373_1_OSN 7 50 Square 373.1 5 25 png, ascii C, UD IAA/OSN filter #E01: Please contact staff 142
143 [SII]_671_1_OSN 6.2 50 Square 671.34 1.02 47.4 png, ascii C, UD IAA/OSN filter #E17: Please contact staff 143
144 [SII]_672_1_OSN 5.9 50 Square 672.46 1 44.8 png, ascii C, UD IAA/OSN filter #E19: Please contact staff 144

Cosmetics: C=clean, UD=undamaged

Last modified: April 20 2023