This file summarizes several instrument specific items for the Magellan/FIRE spectrograph.
The slit edges could shift up to several pixels during the night when you observe a target for a long time and/or when you changing setups during the night. Therefore, we strongly encourage the observers to take some flat fields right after your science exposures every few hours.
PypeIt uses sky OH line for the wavelength calibrations. So you do not need the ThAr calibrations when reducing your Magellan/FIRE Echelle data with PypeIt.