Faint Object Spectrograph & Camera (FOSC) is a versatile instrument, which enables one to do spectroscopy, imaging, and also polarimetric observations of faint celestial objects.

FOSC is based on proven ESO design concepts, and uses a collimator and a focal reducer.Optical filters and grisms (a grating ruled on prism) are inserted in the collimated beam. Slit can be placed at the focal plane of telescope.FOSC for the 3.6 meter Devasthal Optical Telescope (DOT) is designed, developed and assembled by ARIES with inputs from various organizations like ISRO, IUCAA, IIA, and several industries.ARIES-Devasthal FOSC is indigenously designed and developed, for the first time in India.