Due to high launch vehicle costs, space instrumentation designers are constantly pressured to decrease weight and increase reliability of flight hardware. To meet these needs in a spectrometer, the infrared products team at Optical Coating Laboratory, Inc. (OCLI) and the NASA Goddard Space Flight Center (GSFC) have developed an infrared logarithmically variable filter for use in NASA's Pluto Fast Fly-by instrument. The filter and diode array combination replaces the multiple optical elements in conventional spectrometers, resulting in lower instrumentation weight and complexity with no moving parts. The choice of logarithmic rather than linear profile yields constant resolving power on every pixel of the array. Filters were produced in which the center wavelength varied from 1.0-1.581 micrometers , and 1.581-2.5 micrometers over a distance of 1.024 cm. Bandwidth was 0.3% FWHM and overall transmittance ranged from 30% to 50%. This paper discusses the major issues and tradeoffs in the design, manufacture, and testing of the filters. Measurement techniques are presented and comparisons are made between theoretical and measured performance of bandwidth, transmittance, and spectral profile.