Resolving power:
(lambda / delta lambda)

Typical uses:
(...and limitations)

The wavelength coverage is about 0.45um so two grating settings are required to cover the entire window. With a wider slit to reduce slit losses the resolving power is degraded e.g. 0.3 arcsec slit yields R=1700 for an object that fills the slit. One can observe in the M-band with the short camera and the 110 l/mm grating, the maximum exposure time is ~0.5sec with the 0.3arcsec slit; if the objects are sufficiently bright that slit losses are not an issue, use of the long camera allows ~3x longer exposure times (thereby reducing overhead).

Example spectra shown below of a standard star: 4.4 - 5.1um in 1st order

This mode gives approximately the same resolution as the short camera with the 110 l/mm grating, using a comparable slit width in pixels, but with 3x the spatial resolution. Because of the significant slit losses (e.g., a 0.1 arcsec slit is required to match the resolution of the 0.3arcsec slit with the short camera), this mode is only recommended when very high spatial resolution is desired.
 

Example spectra and other figures: