A number of all-reflective large-aperture optical arrangements are described. These configurations form a group of systems whose optical surface figures can be monitored from the effective centers of curvature of the mirror elements. Design specifications are presented for the basic two-mirror f/3 system. Image size versus field angle data indicates that field performance is approximately one-half as good as the refractive corrector Schmidt of equivalent f/no. Geometrical ray trace results for a point source at infinity show an on-axis rms image diameter of 1.5x10-7 radians for the two-mirror system. Practical difficulties of most of the optical arrangements depicted are the close physical proximity of the uncorrected and corrected foci, as well as the large departures of the aspheric corrector surfaces from a reference sphere. These problems are reduced by slowing down the system f/no. But unfortunately they do not disappear completely.