An optical element (12) has aspherical (14) and binary grating (16) optical surfaces. In the preferred embodiment, the optical element (12) is a positive meniscus optical element made of germanium having a useful spectral bandpass in the infrared wavelength region. A telescope (100) includes a first positive meniscus optical element (102), having a convex aspherical surface (104) and a concave binary grating surface (106). A first negative meniscus optical element (107) having a concave binary grating surface (108) and a concave aspherical surface (110) is employed. Next is a positive power lens (112), followed by a second negative meniscus lens (118). In the preferred embodiment, the first negative meniscus optical element (107) and the positive power lens (112) are affixed to a common housing (124), which is removable from the telescope system. Removal of the housing (124) converts the telescope (100) system from a wide-field-of-view telescope (100) to a narrow-field-of-view telescope (40).