>From: Boris Liberman <[EMAIL PROTECTED]> >Now, I'd like to know how many of modern Pentax lenses are original! >optical design? It would seem that some lenses are carry over from >previous generations.
I think a lot of the older M/A/F designs have been replaced by zooms and newer aspherical designs. Some of the basic prime designs are probably pretty old. Same goes for Nikon. The 28/2.8 and 24/2.8 go WAY back, but most of the original AF zooms (which were MF zooms in AF bodies) have been replaced by now. >Some of the K and some of M lenses were very good optically. I mean in >terms of resolution, MTF charts, whatever spec minded people have in >their mind. >Why would Pentax then want to produce same lens (I mean focal length >and aperture) with different optical formula? 1) make it better (sharper, better corrected, etc) 2) make it smaller or lighter 3) make it cheaper to manufacture 4) incorporate new technology not availible before (special glass, vibration reduction, aspheric elements, internal focusing), usually to do one of the first 3 things on the list. >Also, I would like to know about computer involvement in lens design. >When it started? How it changed the world, so to say? Gerjan's book has a picture of a lens-design computer dated to "the early 60s". I've heard that zoom lens design would have been nearly impossible without computers--too many numbers to crunch. Basically, lens design is all optical physics. You can do it all as a mathematical exercise, but it is a very complex one. Computers excel at laborious math. DJE
