Hello folks, I am also on the Olympus camera list, and the nikkor process lenses got a mention there.
I just had a response from a fellow list-member which throws a little monochromatic light on the topic, so I share it. Brian wrote in connection with a Nikkor Process lens: >I visited that, and was suitably awed, then took the link to the base URL.. There I selected one link to a site that looked interesting, and it is of a micro-nikkor with a resolving power of from 700 - 800 lines per mm. Amazing. Here's that URL http://homepage2.nifty.com/akiyanroom/redbook-e/collection/oguri1.html He wrote "The trick here is these lenses only produce that resolution with monochromatic light ("e-line" 530nM) and probably only at full aperture. That is, in designing a photo-lithographic lens (process lens) they don't have to worry about chromatic aberration at all, so diffraction is the limiting factor. More modern process lenses are optimized for different (shorter) wavelengths than e-line and are faster since these lenses are generally diffraction limited, meaning if you stop them down resolution drops substantially. If you tested the OM's (Zuikos) with monochromatic light they would also have better resolution since chromatic aberration would be removed, although they probably have compromised designs, since they must work with full spectrum light. In a normal full spectrum lens, the optimum resolution aperture is where the diffraction fuzziness matches the chromatic fuzziness! If you stop down more diffraction limits while if you open up, chromatic aberration limits." Regards, Tim Hughes Hope that helps people understand these lenses some more. Brian _______________________________________________ Cameramakers mailing list [EMAIL PROTECTED] http://rmp.opusis.com/mailman/listinfo/cameramakers
