| 摘要 |
<p>A substantially unity magnification image forming system includes at least one convex mirror and at least one concave mirror supported with their centres of curvature substantially coincident and means to define a location for an object the image of which after at least three reflections including at least one reflection at each of said mirrors is a real image at a second location and a monocentric meniscus lens between the mirrors to give overall correction for Petzval sum.</p> |
