NIRI Cameras

The science channel of NIRI contains three selectable cameras. The properties of the cameras are summarised in the table below. In addition to defining the pixel scale and field of view, the choice of camera affects the field of view available to the on-instrument wavefront sensor (because the science channel pick-off mirror, past which the OIWFS light shines, is sized to match the science field) and potentially the spectral resolution available with the grisms. Note that with the f/6 camera the unvignetted OIWFS field of view is negligible, and therefore unusable. Thus at f/6 the peripheral wavefront sensors must be used for guiding.

FOVs and pixels size can change by +/- 0.3%, depending on how and where the instrument is mounted; the above are average values. Distortion in the field is much less than one pixel over the entire field.

Last update 2006 September 1; Andrew Stephens, Tom Geballe & Joe Jensen