Archived posting to the Leica Users Group, 1996/11/24
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Jan To put things in optical terms, 0.023mm is 23 microns. This will cause binding and other awful phenomena. In other words, this is what you pay $2795 for. Best regards, Chris At 03:04 AM 11/25/96 +0000, you wrote: >On 24 Nov 96 at 16:11, Marc James Small wrote: > >> At 09:22 PM 11/24/96 +0000, you wrote: >> >> >Shoot. 39mm by 26 tpi is as much a collision of imperial/metric >> >worlds as using 255/75R16 for tire size. >> >It hurts my eyes. Awful!....:-)) >> >> >> But that is EXACTLY the point. It is NOT 39x1mm, it is 39mm by 26tpi. >> Canon made this mistake, too, and that's why they never quite got it right. >> See Dechert's CANON RF CAMERAS for a discussion. Some of the early FED >> cameras show the same mistake. >> >> There was a US ad campaign back in the '60's about a 'silly millimeter' but >> that's really the case here. >> >> It IS 39mm wide by 26 turns per inch. Why Barnack mixed Imperial and >> metric, ich weisse ist nicht. But he did. > >Shoot^2....:-)) >Aside from the nomenclatura: how on earth can 1mm pitch cause >problems where 26tpi doesn't? >26tpi equals 0.977mm pitch (25.4/26), so there is only 0.023mm >difference pro rotation between the systems. Even with a thread >thickness of 1cm, there wouldn't be problems with binding or >whatever. Heck, with a little stubbornness, one can even jam an M42 >male mount all the way down in a T2 female mount (0.25mm difference >pro rotation). > >Truely flabbergasted!....8-)) > >-- >Bye, > > _/ _/ _/_/_/_/_/ _/_/_/_/_/ > _/ _/ _/ _/ _/ _/ _/ > _/ _/ illem _/ _/ an _/ _/ _/ arkerink > _/_/_/ > > > > The desire to understand >is sometimes far less intelligent than > the inability to understand > > ><w.j.markerink@a1.nl> >[note: 'a-one' & 'en-el'!] > >