We present a new instrument for narrow band imaging without the use of conventional interference filters. This instrument will image the OVI doublet at 103.2 and 103.8 nm, the brightest astrophysical emission line from diffuse gas at 300,000 degrees. Gases at this temperature, formed mostly by supernovae blast waves, are key to understanding the energy budget of the galaxy. To date, there are no high spatial resolution narrow-band images of OVI, although some low spatial resolution narrow maps have been acquired with conventional spectrographs. Using the imaging power of a conventional two-optic Gregorian telescope in conjunction with aberration-corrected holography, we can acquire narrow band images with subarcsecond spatial resolution. An aberration-corrected holographically ruled grating in place of the secondary optic is used to diffract the ultraviolet light to stigmatic focus. Additionally, the use of few optical surfaces minimizes the light loss from poor reflectivity of materials in the far ultraviolet (FUV), thereby maximizing instrument sensitivity. This instrument is the first to use aberration-corrected holographic gratings to produce a narrow-band imaging capability in this fashion. We are now developing a rocket payload to demonstrate the power of this technique with particular application to non-radiative shocks in the interstellar medium. We present the optical design, instrument performance, and relevant scientific simulations.