Abstract: A manually operated shutter attachment includes a pair of plate members each having an aperture therethrough secured in spaced parallel relationship with the apertures aligned. A blade member having a body portion and handle portion is pivotably mounted intermediate the plate members with the handle portion extending outwardly of the spacing therebetween whereby the body portion may be pivoted into and out of registration with the aligned apertures in the plate members by manual manipulation of the handle portion. Mounting means are provided on the outer surfaces of both plate members and extend about the apertures thereof for mounting the shutter attachment intermediate a telescope and camera and/or for securing a plurality of similar shutter attachments together. The body portion of the blade member may be opaque to provide a shutter or incorporate an optical filter or lens.

Abstract: Complex aspheric optical surfaces may be made reliably and relatively rapidly by a method in which one surface of a relatively thick glass block is ground and polished to the desired aspheric surface, which may be tested in a system including master optics of the remaining components. This master die block may then be used to generate reverse die plates by drawing thin glass blanks against the configured surface thereof and polishing to an optical flat. These reverse die plates are then mounted on a base die block and deformable glass blanks are drawn against the configured surface thereof and the opposite surface polished to an optical flat. Upon removal, the glass blanks assume a curvature identical to the original aspheric surface of the master die block.