The Imaging Fabry-Perot Spectrograph (IFPS) was a facility instrument built for the 1.8 Perkins Telescope operated by the Lowell Observatory at its Anderson Mesa site located outside Flagstaff Arizona.

The IFPS was designed for two-dimensional imaging spectrophotometric and kinematic studies in the 340-1000nm wavelength range using four 50mm-diameter Fabry-Perot étalons providing low and medium spectral resolutions of R=1200 in the 450-750nm A wavelength range, and R=4500 in three bands covering the 340-400nm, 410-550nm, and 600-700nm.  These resolutions made it applicable to a wide range of galactic and extragalactic imaging spectrophotometry projects. The IFPS has also found use as direct imaging focal camera without the étalons in the beam. 

The IFPS was operated from 1990 until 1998 when OSU sold its share of the Perkins telescope to Lowell Observatory.  The IFPS was the first instrument designed and built by the ISL from conception to commissioning.

Funding for the IFPS was provided by NSF Grants AST-8822009, AST-9112879, and OSU start-up funds for J. Baldwin and R. Pogge