Ernst Leitz Wetzlar Microscopes |
||
|
||
|
This page is linked from my Geological Microscopes website (my web pages are shown in the side bar) Up to a few years ago, I knew very little about Leitz microscopes. Although they are widely used in academia, very few happened to be in the geology labs where I worked. They were not particularly good looking to my eyes, and with this prejudice I thought I would not like to actually own or use one, especially the older black enamel models. What a mistake! In fact, Leitz microscopes are extremely well designed and constructed, including superior optics, and after you have one, you will regard it as a very satisfying and handsome instrument. There is no substitute for quality, and Leitz was at the peak. Information about Leitz microscopes is rather scattered and not always easy to find, so as more photos and links come my way, I will post them here. Because of my background in geology, a lot of the ones I know are polarizing or petrographic versions, but all types will be included. Recently a very fine article about black enamel Leitz scopes made between the late 30s and early 70s, has been written by Gregor Overney and Normand Overney and published in Micscape magazine (March 2008). You should definitely give it a read. The descriptions, texts, documents, and images on these pages are for your information only, and they all have legal copyright protection. You may not use, copy, or change any of files or images on these pages without specific permission from their owners. Also see this repository of Leitz catalogs (free to download, but donations are requested). I am certainly still no authority on Leitz, so if you can correct my errors and add to this page, please contact me. Greg McHone greg "at" earth2geologists "dot" net
|
||
|
A Brief History of Leitz Microscope Manufacturing In 1849, Karl Kellner founded the Optical Institute in Wetzlar, Germany. Telescopes were the original emphasis, but within a few years microscopes took over as the main product. The company hired a very capable engineer named Ernst Leitz in 1865, who soon became a partner. Leitz took over the company in 1869 and renamed it Optical Institute of Ernst Leitz. A revolving mount (turret) for 5 objectives was introduced in 1873, and the company’s reputation grew rapidly. In 1889, the company had 120 employees and produced its 15,000th microscope. In the time between 1889 and 1911, several new products were added to the line, including still and cinematic projectors, binoculars, and a variety of specialist optical equipment. Leitz produced polarizing microscopes after 1885, and by 1890 there was a specialized petrographic model in their catalog. Demand was enough for the first of many special catalogs for polarizing microscopes and accessories in 1893. By the 20th century, Leitz was using the “modern" style of microscope stands, with horseshoe feet and a curving limb to the tubular head, which continued until after the second world war. As did Zeiss and other companies during the 1950s and 60s, Leitz adopted newer styles of microscopes with rectangular hollow frames and feet, internal illumination systems, and modular (add-on) systems for phase contrast, dark field, polarization, photomicrography, and other methods. Like other makers at the time, Leitz used a durable glossy black baked-on enamel finish for most of their microscope models, until finally converting to light bluish-gray colors in the 1970s. In 1912, Dr. Max Berek (1886-1949) joined the Ernst Leitz Company after he had finished his studies in mathematics and mineralogy in Berlin, and he later designed the first Leitz camera lens. Starting in 1924, cameras became an important product for the Leitz company, including the first practical 35 mm camera. Prof. Berek won world fame for his theories and inventions in the area of polarized light microscopy; the Berek compensator and his formula to compute depth of field in microscopes are still in use today. He also invented an anti-reflective lens coating, a great advance in optical resolution. During WWII, the German government revoked his professorship because he refused to cooperate with the Nazi party (he was reinstated in 1946). Dr. Berek worked at Leitz until his death in 1949. Ernst Leitz died in 1920, and his son Ernst Leitz II became the sole owner of the business. During the 1930s and 1940s, Ernst Leitz II and his daughter Dr. Elsie Kuehn-Leitz, both Protestant Christians, arranged for hundreds of Jewish employees and their families to get out of Germany, thus escaping the Holocaust. In 1952, Günther Leitz founded the Canadian Factory to make Leica cameras. After the death of Ernst Leitz II in 1956, his sons -- Ernst Leitz III, Ludwig Leitz and Günther Leitz -- took over management of the Leitz firm . Reports are that no love was lost between Leitz and its main competitor Zeiss, and the two companies tried hard to make their products quite distinct from one another. On the other hand, it is easy to see some design similarities between Leitz scopes such as the black Dialux, and Wild Heerbrugg models such as the M20, and those companies apparently were on friendlier terms. An excellent benchtop research model called Ortholux was developed around 1937, which was larger and more modular than earlier forms. The curving frame reminds us of certain pre-war modernist styles, as also does its competitor the Zeiss Universal. The Ortholux was most successful for higher-budget markets, and so a slightly smaller and less expensive model was produced in the 1950s, called the Dialux. Now sometimes referred to as the Dialux 1, it resembled the Ortholux 1 in form and so is sometimes called a "baby Ortholux." These two models were popular, with a long production run, and they were so well made that many are still in regular use today. By 1970, there were six models of polarizing microscopes marketed by Leitz. From small to large, these were the SM-pol, Labolux-pol, Dialux-pol, Epilux-pol, Ortholux-pol, and Orthoplan-pol. Unlike earlier versions, the Labolux, Dialux, and Epilux had similar stands and other shared parts (still in black enamel finishes), but with different head attachments. Prices in 1971 for stands fitted with middle-level optics ranged from around $1300 for a monocular SM, $3000 for a binocular Labolux, $4100 for a trinocular Dialux, $5500 for an Ortholux, and $6200 for an Orthoplan. Using the consumer price index, $6200 in 1971 is equivalent to around $32,000 in 2005. Even so, it was hard for Leitz to make much profit on the top-of-line Orthoplan, for which they went all-out to be better than any other maker’s equivalent model (for example, the Zeiss Ultraphot). Leitz produced the Orthoplan from 1966 until 1991. Its replacement, the Orthoplan 2, was a little less massive and no longer the top model. In 1973, Leitz Portugal was founded with a factory in Vila Nova de Famalico, near Porto. This plant supplied many microscope heads and eyepieces for Leitz, and now for Leica. During the 1970s, competition increased from several companies in Japan, especially Olympus and Nikon, which were producing modern microscope designs of excellent quality at relatively low prices. Several venerable microscope companies closed, merged, or were bought out in Europe and the USA. Wild Heerbrugg bought majority ownership of the Leitz Wetzlar company in 1974, but Leitz continued to develop their new lines of compound microscopes to replace the older black styles. Styles were changing in the 1970’s, included a gradual switch from 170 mm to 160 mm tube length optics, and later to infinite length, using 45 mm focal length objectives and wide-view oculars. The classic black finish machines designed in the 1950s-60s (still considered by many people to be the best) were replaced with boxy rectangular-frame light gray models such as the HM-LUX, SM-LUX, Dialux, Ortholux-2, and so now the Orthoplan (almost unchanged) more closely resembled other Leitz models. See the photo below. In 1985, four polarizing models were available, still in the light gray rectangular style but with slightly rounded edges and dark trim. The name of Laborlux was used rather than the earlier Labolux, now a source of confusion. The Laborlux 11 Pol (replacing the SM-Lux) was the student model and often used a monocular head, with a 10-watt lamp in the base and fixed condenser. The Laborlux 12 Pol (replacing the Labolux/Dialux pol models) was the lab and clinical model with a more powerful Koehler lighting and upgrade condenser. Both of these used 160 mm tube length objectives. The research line still had the Ortholux 2 Pol BK and Orthoplan Pol, the latter hardly changed from the 1960s but now looking more like other models in its style. Objectives of 170 mm tube lengths were made only for low powers for these machines. Nearly all objectives were 45 mm parfocal length. Leitz retained the Dialux name in the 1980s with the Dialux 20 model, which was advertised as a collaborative effort with Wild to make a worthy successor to the Dialux and Wild M20 (thus the 20 in its name). The Diaplan was introduced in 1985 as a research oriented model one step up from the Dialux 20. In the 1990s, Leitz replaced the Orthoplan with the Aristoplan/Aristomet as the top model. The magnificent Aristoplan was an enormous research microscope marketed to larger well-funded laboratories (a well-outfitted version could exceed $100,000). The last member of the Leitz family retired from the board of directors in 1986. At the beginning of 1987, Ernst Leitz Wetzlar GmbH and Wild Heerbrugg AG merged to form the Wild Leitz Group. The new company had 9,000 employees in several countries. Wild stopped making compound microscopes in favor of Leitz, but continued its excellent stereoscope models as well as other optical equipment. The Wild Leitz Group was broken into smaller companies in 1988, and Leica Camera was split off. The merger of Wild Leitz Holding AG with the Cambridge Instrument Company in 1990 created the new Leica Holding B.V. group. The Leica name is now used for all microscopes (still high in quality), surveying and photogrammetry systems, and other scientific optical instruments, while Leica Camera Group is an independent company. Although student models of Leica microscopes are now made in China, and stereoscopes are from Singapore, some models are assembled from parts and pieces from Leica factories and contract companies in several western countries, including optical parts made in Germany. But they are Leica, not Leitz. Sources: http://www.leicagallery.com/timelineliecahistory.htm http://www.overgaard.dk/leica_history.html http://micro.magnet.fsu.edu/optics/timeline/people/berek.html http://www.microscopy-uk.org.uk/mag/artjan06/pjleitz.html http://www.microscopy-uk.org.uk/mag/artmay06/ma-orthoplan.html http://www.microscopy-uk.org.uk/mag/artmar08/go-leitz.html Leitz Polarizing Microscopes, 1971 catalog
|
||
|
||
|
|
||
|
Leitz microscope line, late 1970s (?) or early 80s. From The Microscope and its Applications, by Determann and Lepusch. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
SM-pol, (mid-1960s?). This earlier version of the triangular base had a rounded back for the SM as well as Labolux. SM or student models had a removable lamp holder or a mirror, either with a pin to fit a hole in the foot beneath the substage. |
|
|
|
|
|
|
|
|
|
|
|
Labolux-pol, circa 1970. The Laborlux and Dialux had a triangular base thick enough to hold a lamp tube, which reflected in a mirror in the field lens through a removable field diaphragm up toward the condenser. An external power transformer is required. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Dialux-pol, circa 1970. The camera is a Nikon 990 digital with a relay Leitz Periplan 10x high-eyepoint eyepiece, which has a thread that screws on to the camera (a case of serendipity). |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Five rotary wave compensator plates (4x12 mm) were made by Leitz (as listed and priced in their 1971 pol scope catalog). All look exactly alike and must be distinguished by testing, or by their serial numbers. Leitz-now-Leica in Wetzlar can tell you which is which, although they might charge a fee. |
|
|
|
|
|
|
||
|
|
|
|
|
||
|
||
|
|
|
|
