Each LUCI instrument has 3 internal cameras which allow the user to access a variety of pixel scales. While any camera can be used in any mode, they each have a preferred usage for which they were designed. The cameras and associated details are listed below.
|Recommended Usable Field||Primary Use|
|N1.8||0.2500±0.0040||0.2500±0.0040||4′ X 2.8′||Spectroscopy|
|N3.75||0.1178±0.0030||0.1190±0.0030||4′ X 4′||Imaging|
|N30||0.0150±0.0005||0.0150±0.0005||30″ X 30″||AO|
The N1.8 camera is the standard spectroscopic camera for seeing-limited observations. The user sees the same vertical 4′ field of view (FoV) as with the N3.75 camera, but the coarser sampling puts that image across only the central 970 pixels. The horizontal restriction in the FoV to 2.8′ is because the slit masks are held in a cylindrical shape to follow the curved telescope focal surface along the Y direction. As the user moves off the central field in the X direction, the slitlets on a MOS mask become increasingly out of focus with respect to both the telescope (giving higher slit losses) and the instrument (decreasing the effective resolution). This camera can be used for imaging, but the distortions and color correction are not as good as in the N3.75 camera.
The N3.75 camera is the standard imaging camera for seeing-limited observations, including the acquisition imaging needed for longslit or MOS mask alignment. At 0.12″/pixel it is well-sampled for almost all conditions at the LBT, and covers a 4′ by 4′ FoV. It has relatively low distortion and is well corrected for color across all NIR bands. Even in the available narrowband filters it reaches the background limit on sky in short exposure times. This camera is also used for working with ARGOS, as well as Enhanced Seeing Mode (ESM). It can also be used for spectroscopy, the trade off as compared to the N1.8 camera is between resolution and free spectral range.
The N30 camera is the standard camera for adaptive optics imaging and spectroscopy. The 15 mas/pixel scale gives Nyquist sampled diffraction-limited images at one micron. The N30 cameras in LUCI1 and LUCI2 are slightly different. In LUCI2 the camera is made with metal mirrors. The N30 Camera in LUCI1 was constructed with glass mirrors. Both Both cameras produce diffraction limited images with high Strehl ratios.