WFI Overview

The WFI is a joint project between the European Southern Observatory(ESO), the Max-Planck-Institut für Astronomie (MPI-A) in Heidelberg (Germany) and the Osservatorio Astronomico di Capodimonte (OAC) in Naples (Italy).

WFI in a Nutshell

Field of view  34'x33'
Pixel scale  0.238 arcsec/pixel
Detector  4x2 mosaic of 2kx4k CCDs
Filling factor  95.9%
Read-out time  27 seconds
Read-out noise  4.5 e-/pixel
(Inverse) gain  2.0 e-/ADU
Dynamical range  16 bit
Full-well capacity  >200,000e-
Telescope aperture  2.2 m
Telescope focus  Cassegrain (f/8)
Instrument F ratio  5.9
Wavelength range  Atmospheric cutoff to 1 micron
Intrinsic image quality  0.4 arcsec
Geometrical distortions  <=0.08%
Slitless spectroscopy  4.5 (5.7) nm resolution at 400-640 (650-850) nm
Raw data format  FITS (with extensions), 142 Mbyte/file

The WFI chips and corresponding pixel values

 

In the full field of view of the RTD, the southeasterm most light-sensitive pixels of each CCD fall on the following X/Y coordinates:

CCD No. X Y
50 2 4130
51 2149 4127
52 4293 4125
53 6437 4128
54 6437 3
55 4292 1
56 2149 1
57 5 6

The WFI gaps

WFI Topography