High-resolution imaging systems are provided. In one embodiment, an imaging system based on a Cassegrain or Schmidt-Cassegrain objective, with coaxial primary and secondary mirrors, is provided with a microdisplacement mechanism acting on the secondary mirror to displace the image on a focusing array. In another embodiment, two co-axial Cassegrain-type objectives are provided one within the other with a common focal plane array, which therefore detects combined wide field-of-view and narrow field-of-view images.