Narrow Field Imager (NFI) is a compact externally occulted coronagraph with a similar field of view to SOHO/LASCO-C3: from 6 to 32 solar radii on the sky. The external occulter blocks direct sunlight from entering the main optical aperture, which views the corona and starfield around the Sun using a compound lens system. Polarization is resolved using a polarizing filter wheel (PFW) assembly, and the image is digitized using a CCD camera assembly (CCA) with a 2kx2k active detector area. The PFW and CCA designs are common to both instruments.