The article concerns a mirror-lens objective for astrophotographic apparatus which consists of a parabolic mirror and a lens system set in a beam of light rays convergent to its focus. The apparatus has the distinguishing feature that for increasing the field of vision the lens system is designed from three lenses of the meniscus form separated by air spaces turned with their convex sieds toward the photographic plate. Equations and other data are given. (Author)
展开▼