Archived posting to the Leica Users Group, 2004/05/06[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]
At 05:34 PM 5/6/04 -0400, Max Weisenfeld wrote: >I thought Stolze stops were fairly close to f/stops ... Stolze 5 between f/4 >and f/5.6, for example. The markings on the Photar relate to much smaller >openings, and much less light passage. I have run some casual tests, and >the difference seems to be in the range of 6 stops (metered at 1/30 @ f/2.8, >shot at 8 seconds at f/(or whatever, stolze)8). > >I do not have access to Leica Manual 15th edition, so any help would be >appreciated. Macro lenses have been made by a variety of manufacturers. The most noted are those from Zeiss (Mikrotars and Luminars), Leitz/Leica (Milars, Micro Summars, and Photars), Nikon, Canon, and the Reichert Neupolars, along with the Bausch & Lomb Micro-Tessars. These lenses are all modified microscope objectives and provide great magnification with a flat field. Their depth of field is minute, so great care is required to bring the best out of them. Almost all of these lenses are made in the standard microscope objective mount, the so-called "Royal Screw" (it is actually the Royal Microscope Society's Screw Mount as adopted at and 1869 conference in, I believe, Paris or Brussels.) This mount is 0.7965" (20.1mm) x 36 t.p.i. Whitworth and is the standard world-wide. Some of the larger Leitz/Leica and Zeiss macro lenses, however, do require a special mount. These are generally marked not in conventional f/stops but in Stolze stops. These are geometric in progression and fit within the standard f/stop system. (See Wildi's work on the Hasselblad system for discussion; my copy is not at hand.) Stolze developed the comprehensive scale for f/stops which we use today when he was employed by Zeiss, though his initial scale was that of the European stops soon rejected by Zeiss in favor of their own International Scale which we use today. I can dig up a lot more informtion on this point if someone wishes to know the details! RMS adapters are available readily from scientific supply houses (Edmund Scientific, for instance, sells an RMS to T-Mount adapter). I can use my macro lenses with my Leica M (via the Bellows II or, in some cases, directly on a Viso II/III) or on my Hasselblad 2000 FC/M. These macro lenses provide coverage to about 4"by 5" and Linhoff even markets an adapter to fit them to their LF cameras. If anyone wants to know more, I can provide a lot more information. I own a comprehensive (never say complete!) set of Luminar and Photar and Mikrotar lenses and a number of Micro Summars, Milars, and Micro-Tessars. I still lack the Repro Summar, part of the breed, but this has been low on my priorities over the past several years. There are also the oddball lenses, such as the Leitz 12cm Photar datring from the 1920's and the later Zeiss S-Tessar, S-Biogon, S-Planar, and S-Orthoplanar lenses. Some of these guys are great: the 4/60 S-Planar makes a grand enlarging lens, for instance. Marc email@example.com FAX: +540/343-7315 Cha robh b?s fir gun ghr?s fir!