A method and system that objectively measures the convergence and focus of a 2 or 3 spatial light modulator (SLM) projection display. The system uses five (5) CCD cameras and a frame grabber to store red, green, and blue (R-G-B) data from selected pixels located in the corners and center of the projector's field-of-view. The horizontal and vertical locations for the R-G-B pixels at each of the five locations is determined and the delta () displacement of the green and blue pixels, relative to the reference red pixel, is calculated and used to converge the image. The optical focus of the system is also determined using a Fast Fourier Transform (FFT). The FFT is performed on this same data and a power spectrum summation beyond the first mimima is determined. The focus is then adjusted to maximize this value.