This paper studies a modified photographic cell with symmetrical short gaps between a high-resistivity detector plate and two planar electrodes. The photographic system with a modified cell is designed to optimize the parameters for the enhancement of the resolution in such applications. The spatial stabilization of the current in the modified cell with a planar GaAs photodetector is studied in a wide range of gas pressure values at 101-342 Torr. Characteristics of the photographic system are obtained both without and with illumination of the detector plate with light of a particular wavelength range used to control the photoconductivity of the material. The current-voltage characteristic (CVC) and the photographic cell response are recorded.