I've been reading a bit lately about how the P & S soft-focus lenses achieved their look through hand-finishing the lenses with aspherical surfaces, and that the "induced imperfections" (or whatever you may want to call them) are visible when the lenses are disassembled. Just out of curiousity, a question to those of you lucky enough to own one of those rare gems: can you see evidence of those hand-finished surfaces on the lenses?
And for the curious among you, a couple of the references I've run across lately...
From the Cooke Optics website:
"The original Pinkham & Smith lenses achieve their distinctive soft focus in a manner different from other lenses. Using the traditional glass available at the time, craftsmen hand-corrected multiple surfaces of the lenses to achieve their unique soft focus look. The introduction of aspherical surfaces gave Pinkham & Smith lenses a higher-order spherical aberration that results (when the lens was used fully open) in an image with both very high resolution and a self-luminescent quality. Cooke has reproduced the unique performance of these hand aspherized lenses using modern design techniques that duplicate this unique soft yet high-resolution performance exactly."
And from Barbara Lowery on the Greenspun lf archive, obviously talking about the PS 495 and its predecessors, at the bottom of this thread:
"What gives the Pinkham & Smith lenses their distinctive look is the reliance on hand correcting multiple surfaces of the glass, which is very different from what other lens manufacturers did. The reason P&S could get away with hand rubbing each and every piece of glass, was probably because they never made their lenses in quantities great enough to make it unfeasible to do so. It created (what our Academy Award winning chief optical designer at Cooke says is) a higher order of spherical abberation that gives the highlights that unique Pinkham & Smith luminescent quality."
"I originally thought that by the time the Visual Quality IV was made, it would have become an assembly line affair - I was proven wrong. The Visual Quality IV lenses Cooke took apart in England to examine revealed hand figured surfaces."