Segmented mirrors with four and six segments over the full aperture are discussed with regard to the figure correction capability for both moment-and piston-type actuators. The number of actuators, ranging from 48 to 480 DOF over the full aperture, is analyzed for residual error for specific Zernike polynomial input errors. Tradeoff study results show that a very thin mirror will reduce required actuator forces, but if the mirror becomes a membrane and loses its bending stiffness, the figure correction capability degrades rapidly. In general, moment and piston actuators each have regions where one is superior to the other, but no generalization can be made for the cases presented in this paper. The results for a 65-cm-diameter mirror show that 50 to 100 actuators will provide very good wavefront correction capability for a rather broad spectrum of Zernike polynomial input errors.