Abstract: A target plate is provided in the operating field of view of a microscopic operating system having a plurality of target patterns thereon. These target patterns include scaled rulings, to which an operating element of the system is aligned, and reflective portions for calibrating the optical elements of the system to assure even illumination of the field of view and minimal distortion. Additional target patterns include centerline rulings which intersect at right angles for calibration of Theta alignment of an operating element, and at least one matte surface for examination of the pattern recognition capability to determine contrast and video information quality. At least one checkerboard pattern of alternating reflective and non-reflective surfaces and at least one continuously reflective surface may be provided to calibrate distortion, focus, illumination, and contrast.