TECHNES Encyclopedia Database

Lens craft was a decidedly imprecise practice in the 19^th century. As cinematographer Karl Brown describes the process in his 1922 article “Modern Lenses,” in the old days, “the optician, guided by experience and a more or less trustworthy intuition, would grind lenses by way of a trial, combine them, and then proceed to vary the curvature of the lenses and their combinations until the desired result was attained in a more or less complete manner.”^[5] Instrument making was seen as “a form of highly-skilled handicraft” and instrument makers in Germany, France, and England found that “the use of machines tools was more appropriate for industrial manufacturing than for small precision industry.”^[6] While an effective lens could be made by hand, it was often a long and imprecise process that was not suitable to mass distribution or practice.

Machine-tools operated by small steam engines were used routinely in lens production after the 1850s, but the lenses produced by these machines were largely considered to be of inferior quality to the hand-made variety and were generally used for mass-produced instruments like spectacles, theater binoculars, or cheap telescopes.^[7] Belief in high quality optics was usually attached to a single craftsman who could intuitively manage the distortions of a lens.

A lens’ quality was closely tied to the reputation of its artisan (a stark contrast to the standardization and objectivity that characterizes contemporary optics). In these contexts, trust in an optician – a person whose quality rested on their craft, rather than essential principles of optical design – was a means to establish trust in vision.

The lack of faith in lens-based vision was also part of a broader cultural anxiety around the relationship between sight and knowledge. Developments in nineteenth century optical science challenged previously stable beliefs about the objectivity of human vision. Scientists such as d’Arcy, Roget, Brewster, Faraday, Plateau, Stampfer and Babbage carefully observed how “the eye could be tricked into creating visual superimpositions, or even illusions of motion, by viewing rapidly changing images.”^[8] Investigations of color, motion, sight, and light contributed to the idea that models of perspectival representation “no longer had the legitimation of a science of optics.”^[9] Vision increasingly came under scrutiny and lost its stability as a privileged form of knowledge and knowing. Rather than offering a clear way to see the world, lens-based instruments introduced further questions about the possibility of objective knowledge.

These problems and questions about distortion were seen as most crucially an issue when it came to microscopy. Microscopes were seen to have no place in serious scientific work well into the 1830s. As Popular Science noted in its 1872 review of The Lens: A Quarterly Journal of Microscopy and the Allied Natural Sciences, prominent physiologists denied that microscopes had any use in scientific work as late as 1839.^[10] Professional distrust of the microscope lessened during the 1830s as German and Central European biologists began to use newly available achromatic microscopes. However, early treatises on microscope practice consistently emphasized the importance of “proper observational technique.”^[11] There were no reliable and repeatable explanations about lenses that could prove how “the balls, blobs, rings, halos and general fuzziness could exist and still not threaten the basic premise of microscopy: that, properly interpreted, the microscopist could believe what he saw.”^[12]

For most of the nineteenth century, the microscope was “a piece of technology that artisans could build, microscopists could use, but physicists could not understand.”^[13] Of the few precision instruments sold at Zeiss in the 1840s and 1850s, the belief in their quality was largely a belief in Zeiss’ journeyman, August Lober, who made the difference between optical quality and “blurry junk.”^[14] Similar kinds of beliefs applied to camera lens makers. While firms like Dallmeyer, Ross, and Voigtlander sold high-quality camera lenses that were precision objects in their own right, the quality of these lenses was based on the reputation of the firm more than from a firm belief in the application of scientific principles of construction.

Ernst Abbe

Ernst Abbe was a key figure in Zeiss’ effort to reduce distortion and improve trust in optical science. Abbe came to the University of Jena in 1863 on the basis of his thesis on the calculation of errors in scientific observations.^[15] He was both a research director at Zeiss, as well as a socially conscious labor reformer.

It is difficult to overstate the influence that Abbe had in the history of both optics and nineteenth century instrument culture, and there are many sources that more closely examine his life and history. For the purposes of this entry, one of his significant contributions was persuading the broader German scientific community of the progressive benefits of theoretical optical science. Instruments, by explaining life in terms of mechanical principles, could give rise to new scientific research and social progress.

But there were professional doubts about the reliability of certain lenses. As late as the 1870s and 1880s, the prevailing belief remained that microscope and photographic lens objectives were “too difficult to be constructed in accordance with [purely] theoretical requirements.”^[16] Photographic lenses like the Petzval Portrait Lens and the Steinheil Aplanat were constructed according to theoretical designs as early as the 1860s. But, by and large, these successes “did not convince the optical world of the need for a good theoretical background.”^[17] Nineteenth century opticians, as Rudolph Kingslake historicizes, were “far too willing to make empirical trials and put together a series of lens elements, hoping that a miracle would happen and that their system would turn out to be better than those currently available.”^[18] Through Abbe’s work, Zeiss cultivated a belief in the progressive benefits of theoretical science for the construction of lens-based instruments. These changes were also supported by Zeiss’ advertising of optical theory as well as Zeiss’ collaboration with universities and research institutions, which legitimated these instrumental tools through their use in professional practice.

By pursuing optics as a systematic science, a problem started to come into focus: if distortions were to be removed from optical systems, the solution was not just to find a new way of arranging existing types of optical glass into a lens. To improve their lenses, Zeiss needed to make new kinds of optical glass.