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Camera optimization

Figure 2.3: Camera layout. All-spherical surfaces and only standard glasses (Ohara S-FPL51, S-BSL7) ensure high quality, high transmission and low cost. Note the tilted focal plane to correct for axial chromatism.
\includegraphics[width=10cm]{CAOS/camera_SESO.eps}

Many efforts has been spent during optimization process searching for a simple, efficient, low cost F/2.1 camera design (figure 2.3). After many trials, we found a good solution with only two different glasses (Ohara S-BSL7/S-FPL51 or equivalent Schott BK7/N-PK52). Five lenses are mounted in three groups (a doublet, two separate lenses, a field flattener acting also as dewar window). All surfaces are spherical or plane. Due to the fixed spectral format, axial chromatism has been corrected tilting the focal plane. Proper A/R coatings will be applied at each air-glass interface to maximize transmission. Optical prescription are given in table 2.1. Below camera first order parameters are listed:

Entrance diameter: 100 mm
Effectice focal length: 213 mm
F/number: F/2.1
Field of view (diameter): 7.5$^{\circ}$
Wavelength range: 390-710 nm


Table 2.1: Camera optical prescriptions. Radii, thicknesses and free diameters are measured in millimeters.
Surface Radius Thickness Material Free diam
Object - $\infty$ - -
Pupil (stop) - 15.000 - 106
1 299.957 25.000 S-FPL51 112
2 -131.845 1.000 - 112
3 -130.009 10.000 S-BSL7 112
4 $\infty$ 344.586 - 112
5 91.285 30.000 S-BSL7 104
6 $\infty$ 1.000 - 104
7 64.249 23.000 S-BSL7 90
8 66.993 32.393 - 70
9 -194.150 8.000 S-BSL7 54
10 $\infty$ 15.000 - 54

The Société Europénne de Systèmes Optiques is in charge for the realization of the camera and delivering is expected at the end of May 2005.


next up previous contents index
Next: High and Low Resolutions Up: CAOS - The new Previous: Echelle, cross-disperser and spectral   Contents   Index
Innocenza Busa' 2005-11-14