Archived posting to the Leica Users Group, 2006/11/04[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]
At 09:21 PM 11/4/2006, Rose Scollard wrote: >wow - that's a lot of variables!!!! thanks for the link. David Rose There are hundreds of adapters for Visoflex, many of them not readily known as they were marketed through the microscope side of Leitz and not through the camera dealers. To complicate the issue, Leitz used three different sets of catalogue codes -- the alphic one such as OUBIO used into the 1960's and the current numeric code (which has several permutations, but let that one rest for now!). In addition, Leitz was beginning to convert to yet a third system, numeric, when the Second World War broke out, which forced them to stay with the alphic system they had been using. Still, catalogues and the like from the late 1930's list both the alphic code and the numeric code from this abortive system. This switchover complicates things more than a bit, as many of the adapters were in production from the late 1930's to the untimely and unseemly death of the Visoflex system in 1984. I have been compiling a list of Visoflex adapters for the past decade and I would guess that it is only about half done, as I have yet to work my way through the process of acquiring and analyzing the microscope catalogues. There were two basic families of Leitz reflex housings. First came the PLOOT, in two versions, and the Visoflex I, which could be had in both LTM and M BM. This had an optical registration of 62.5mm (that is, it required lenses with a back-focus which could accomodate the camera's depth plus this distance -- that is, 28.5mm + 62.5mm, for a total back-focus of 91mm. (The lenses stayed the same: M mount Viso I's were actually 63.5mm in depth, as the depth of an M camera is 1mm less than the LTM bodies to allow the use of lens adapters of 1mm thickness.) Then came the Viso II, IIa (two versions, yet again), and III, which only had a depth of 40mm. Something had to make up that 22.5mm difference, and the OUBIO was the solution, as it is, essentially, a 22.5mm spacer. Later Visoflex lenses were made a bit longer to accomodate this. I suspect there are exceptions, but a good working hypothesis is to check on how the lens is marked: if it is in cm, it requires as OUBIO and, if it is marked in mm, it does not. But that is a working hypothesis I just, as Mark Rabiner might say, just worked out in my head, and I've not checked all my Viso lenses to be certain of this -- I just strongly suspect this to be the case. There is a lot of Visoflex knowledge on the LUG, and a bit of Visoflex deriding, as well. Bear with it: the Visoflex allows all sorts of flexibility with a Leica camera, such as macro work (20X enlargements, for instance) and tele work -- I can readily adapt my M6 to one of my telescopes and get a 2100mm long-focus lens! It is a system well worth learning. Ask, and we shall do our best to answer. Marc firstname.lastname@example.org Cha robh b?s fir gun ghr?s fir!