An analytical model for crosstalk is developed for an infrared scene projector that utilizes a deformable-mirror device as an infrared spatial light modulator. Partial-coherence effects that result from the physical layout of the projection system are included. Crosstalk is determined by defining a crosstalk ratio in the projected image. Crosstalk-ratio calculations are carried out for monochromatic and blackbody projection sources over the 3- to 5-μm wavelength band. The results predict crosstalk ratios of 260:1, 1200:1, and 2400:1 for deformable-mirror pixels of 50, 100, and 150 μm when a blackbody source is used in the projection system. Crosstalk performance is improved at shorter wavelengths and for larger deformable-mirror pixels. The results of a proof-of-principle experiment are included to verify the feasibility of a deformable-mirror device in the projection system.