An MWIR spectral imaging sensor based on dual direct vision prism (DVP) architecture is described. This sensor represents a third generation of the Chromotomographic Hyperspectral Imaging Sensor (CTHIS). In the new sensor, a direct vision prism is synthesized by the vector addition of the spectral response of two matched, but independently aligned DVP's. The resulting sensor dispersion varies from zero to twice the single prism dispersion, as a function of the angle between the dispersion axes of the two prisms. The number of resolved channels, and the related signal strength per channel, also adapts with this angle. The "synthesized prism" projects a spectral image onto the focal plane array of an infrared camera. The prism is rotated on the camera axis and the resulting spectral information is employed to form an image cube (x, y, λ), using tomographic techniques. The sensor resolves from 1 to 105 spectral channels, between 3.0μm and 5.2μm wavelength. Spectral image data and image reconstruction is provided for standard test sources and scenes.