Imaging: Filters and Objectives

Filters

      Wheel 1            Wheel 2      
Pos.   Name Central wavelength (µm) Width (µm) Width(%) Plot   Name Central wavelength (µm)  Width (µm) Width (%) Plot
1    Open            NB 2.28  2.280  0.030  1.4 Gif,ASCII
2    NB 2.19  2.195  0.03  1.37  Gif,ASCII    NB CO  2.336  0.03  1.32  Gif,ASCII
3    NB 2.09  2.09  0.02  0.96  Gif,ASCII   F ocus wedge         
4    NB 1.19  1.187  0.01  0.84  Gif,ASCII   Open         
5    NB 1.06  1.061  0.01  0.94  Gif,ASCII   NB 1.08  1.083  0.0164  1.48  Gif,ASCII
6    Closed            NB 1.21  1.215  0.018  1.5  Gif,ASCII
7    Z  0.9  0.14  16      NB Fe[II] J  1.257  0.019  1.48  Gif,ASCII
8    GBF  0.925  cut-on        NBPbeta  1.282  0.019  1.5  Gif,ASCII
9    GRF  1.424  cut-on        NB [FeII] H  1.644  0.025  1.52  Gif,ASCII
10    Js  1.24  0.16  13  Gif,ASCII   NB 1.71  1.71  0.026  1.52  Gif,ASCII
11    J  1.247  0.290  23  Gif,ASCII   Closed         
12    H  1.653  0.297  18  Gif,ASCII   NB HeI K  2.059  0.028  1.36  Gif,ASCII
13    Ks  2.162  0.275  13  Gif,ASCII   NB H2 S1  2.124  0.028  1.32  Gif,ASCII
14                NB BrGamma  2.167  0.028  1.29  Gif,ASCII
15                NB 2.25  2.248  0.03  1.3  Gif,ASCII
Table 1. SOFI filters.
Encapsulated Postscipt format
Figure 1. SOFI filters.

The solid (red) lines indicate the currently available broad-band JHKs filters. The short-dashed (magenta) lines are the available narrow-band filters. The long-dashed (red) lines show the soon to be commissioned Js filter (top panel) and the typical broad K filter (Persson et al. 1998 A.J. 116, 2475; Table 10). The dotted (blue) line is the atmospheric transmission model for Mauna Kea, for Am=1.0 and water vapor column of 1mm (Lord, S.D. 1992, NASA Technical Memor. 103957; courtesy of Gemini Observatory). The data for the plot and the SuperMongo script are available here.

Objectives

Name Field (arcmin)  Scale (arcsec/pixel) 
Large Field (LF) 4.9 x 4.9 0.288
Small Field (SF) 2.4 x 2.4  0.144 
LF + Focal Elong. (FE) 2.4 x 2.4  0.144 
Spectroscopic Objective (SO) 4.5 x 4.5  0.273 
High Resolution (HR)
(not offered)		 1.2 x 1.2 0.072
Table 2. SOFI Imaging modes.

Image Quality

The image quality of the Large Field mode is checked regularly. You can retreive some information :