Along several years, more than a decade from 1974/75, CZ manufactured QBM lenses and Contax/Yashica lenses simultaneously (including CZ lenses made by Rollei and Yashica), I think that it would not be so difficult for an experimented technician to replace a Contax/Yashica adapting a QBM mount to the original C/Y lens for some reason, perhaps the verb is to replace the mount and not to convert it. Any adaptation work is possible, you could do it replacing the mount or manufacturing an adaptor, the issue is the cost and the relationship with the benefit of course. Carlos 2010/8/20 John Wild <JWild@xxxxxxxxxxxxxxxxxxxxxx>: > Carlos, > > I have wondered if it is possible to convert a Zeiss CY mount lens to QBM as > mentioned in a previous listing. > > John > > > On 20/08/2010 14:54, "CarlosMFreaza" <cmfreaza@xxxxxxxxx> wrote: > > >> >> Some earlier CZ lenses for the Contax/Yashica mount have identical >> diagrams and technical data regarding the QBM CZ lenses, the Planar >> 1,4/50 is a sample, however CZ upgraded the design for some >> Contax/Yashica lenses afterward. >> >> Carlos >> > > --- > Rollei List > > - Post to rollei_list@xxxxxxxxxxxxx > > - Subscribe at rollei_list-request@xxxxxxxxxxxxx with 'subscribe' > in the subject field OR by logging into www.freelists.org > > - Unsubscribe at rollei_list-request@xxxxxxxxxxxxx with > 'unsubscribe' in the subject field OR by logging into www.freelists.org > > - Online, searchable archives are available at > //www.freelists.org/archives/rollei_list > > --- Rollei List - Post to rollei_list@xxxxxxxxxxxxx - Subscribe at rollei_list-request@xxxxxxxxxxxxx with 'subscribe' in the subject field OR by logging into www.freelists.org - Unsubscribe at rollei_list-request@xxxxxxxxxxxxx with 'unsubscribe' in the subject field OR by logging into www.freelists.org - Online, searchable archives are available at //www.freelists.org/archives/rollei_list