CTIO 3x3-inch and 4x4-inch FILTERS

A. Walker 4 April 1999
awalker@ctio.noao.edu

The standard filter size for the 0.9-m and 1.5-m CFCCD is 3x3 inch, which are mounted in two filter wheels which each can hold up to 8 filters (or 7 plus clear). We have a single wheel which can hold up to 5 4x4 inch filters which can be installed in place of one of the 8-position wheels. At the Schmidt, and the 4-m PFCCD (now retired) 4x4 inch filters are required in order to avoid vignetting. We do have adaptors to allow the use of smaller filters (eg 2x2 inch), if the vignetting is tolerable, but see the warning note at the head of the filter list. The BTC and Mosaic II imagers, used at the 4-m prime focus, take filters 5.75 x 5.75 inches (146x146 mm) and nominally 12 mm thick.

  FILTER    SIZ Thick Cent. fwhm  Trans FILTER SET &  COMMENTS
  /width    (") (mm.) (A.)  (A.)   (%)
                  
  3513/628  4x4                         SDSS u           
  3530/280  4x4  9.15 3530   280  37.14 u Stromgren
  3570/660  3x3       3570   660  80.59 U liq.CuS04 Tek set#2
  3575/600  3x3  9.09 3575   600  74.21 U liq.CuSo4 Tek set#1
  3580/610  4x4  9.32 3580   610  74.66 U Liq.Cuso4 set#1 4mts
  3623/605  3x3  8.83 3623   605  67.66 U liq.CuSo4 Tek set#3
  3960/100  4x4                         Ca H&K line filter   
  3996/1042 3x3  8.11 3996  1042  62.70 C Wash.
  4000/1030 4x4  8.45 4000  1030  62.45 C Wash.
  4118/146  4x4  9.87 4118   146  52.04 v Stromgren. 4x4
  4185/1030 4x4  5.40 4185  1030  70.44 B Harris set#1 4mts
  4202/1050 3x3       4200  1050  66.16 B Tek set#2
  4203/1050 3x3  5.26 4200  1050  66.72 B Tek set#3
  4201/1050 3x3  5.17 4200  1050  66.48 B Tek set#1
  4340/980  3x3  6.38 4341   980  60.33 B Harris set 1
  4357/1665 4x4  3.65 4357  1665  88.19 B Tyson "J"    
  4345/980  3x3  6.33 4345   980  60.85 B Harris set 2
  4200/1050 4x4                         B Set# 2 Schmidt
  4697/196  4x4  9.85 4697   196  71.27 b Str”m. 4x4
  4759/1430 4x4                         SDSS g
  4940/700  4x4  8.95 4920   670  93.09 Gunn g
  5025/1023 3x3  8.08 5025  1023  88.60 M Wash.
  5019/50   4x4  7.83 5027    50  79.48
  5040/990  4x4  8.25 5040   990  88.23 M Wash.
  5118/900  3x3  5.05 5118   900  81.39 g Gunn-T
  5130/155  4x4  7.76 5121   133  84.13 DDO 51 Wash. set
  5295/1590 4x4  5.24 5292  1625  90.66 HST "V"      
  5362/895  3x3  6.14 5362   895  76.80 V Harris set 1
  5370/900  3x3  6.18 5370   900  75.64 V Harris set 2
  5438/1026 3x3       5438  1026  91.91 V Tek set#2
  5443/1060 4x4                         V set#2 Schmidt
  5443/1060 4x4  5.12 5443  1060  88.50 V Harris set#1 4mts
  5475/1000 3x3       5475  1000  87.71 V Tek set#1
  5497/241  4x4  9.74 5478   244  70.83 y Str”m. 4x4
  6120/140  3x3  7.97 6115   135  85.89 Supernova
  6130/590  4x4  8.35 6130   590  56.19 T1 Wash.        .9% leak at 1.2u.
  6152/625  3x3  8.21 6152   625  58.06 T1 Wash.         1% leak at 1.0u.
  6265/1483 4x4                         SDSS r
  6410/1470 3x3  5.23 6410  1470  81.76 R Tek set#3
  6425/1500 3x3  5.25 6425  1500  79.69 R Tek set#1
  6437/1525 4x4  5.22 6437  1525  81.38 R Harris set#1 4mts
  6437/1525 4x4                         R set #2 Schmidt
  6400/1450 3x3       6400  1450  81.09 R Tek set#2
  6475/1600 3x3  6.18 6475  1600  81.70 R Harris set 1
  6493/1445 3x3  6.15 6493  1445  77.00 R Harris set 2
  6560/900  4x4  9.19 6495   900  94.95 Gunn r
  656375-3  3x3  5.61 6559    64  89.37
  656375-4  4x4  5.54 6567    68  82.32
  660075-3  3x3  5.57 6598    69  87.77
  660075-4  4x4  5.57 6600    67  84.77
  6728/1000 3x3  5.05 6728  1000  93.83 r Gunn-T
  6738/50   4x4  7.97 6744    50  87.83
  7734/1500 4x4                         SDSS i
  8120/1500 4x4  9.22 8065  1600  86.60 Gunn i
  8067/1485 3x3  6.11 8067  1485  95.49 I kc Tek set#3
  8075/1500 3x3  6.13 8075  1500  95.53 I kc Tek set#1
  8075/1500 4x4  6.19 8075  1500  94.09 I kc set#1 4mts
  8118/1415 3x3       8118  1415  96.63 I kc Tek set#2
  8100/1500 3x3  5.08 8100  1500  93.00 i Gunn-T
  8300/2500 4x4  5.43 8310  2560  98.73 HST "I"      
  9100/1400 4x4                         SDSS z
  9100/1400 4x4                         z Gunn
  9100/1400 3x3                         z Gunn