![]() ![]() It’s easily identified by its mount, and by its heavy chrome-plated brass construction. The pre-war Biotar 58mm only released in Exakta mount, and it’s a very different lens compared to the later models. Throughout the production period of the lenses, the barrel and aperture diaphragm changed and the biggest differences show in how the aperture is operated progressing from entirely manual, to pre-set and then finally to semi-automatic. There are four basic models of the original Biotar, several variations of these, and the reproduction made by Oprema Jena. And nearly all the Japanese lens manufacturers used the Double Gauss design of the Biotar as the basis for their fast lenses. Nine years later, when the Japanese started producing SLR cameras, virtually all of them except Nikon, Topcon and Canon adopted the M42 screw mount that was invented for the Contax S. The 58mm focal length provided 1:1 viewing on the Contax S focusing screen. It’s reported that the speed of the lens was necessary because the viewfinder of the Contax S was dim, but I suspect that the designers simply attempted to get as much performance out of the pre-war design as possible. The very first of what we now call a “kit lens” to come with the Contax S was the Biotar 58mm f/2 lens, which had to be specifically developed for the camera because the internal mirror meant that the flange focal distance of the lens had to be shorter, and the focal length adapted for use with a prism. ![]() It was another nine years before the Japanese caught up by developing the Nikon F, Canonflex, the Pentax Spotmatic and other eye-level SLRs with interchangeable lenses and focal-plane shutters. This revolutionary camera was also the first to use what is now known as the M42 Mount, Universal Screw Mount or Pentax mount. Incredibly, only a few years later in 1949 Carl Zeiss Jena rose from the ashes to release the Contax S, the World’s First 35mm eye-level single lens reflex camera with a glass prism finder and interchangeable lenses. Plans that had been developed for an SLR camera conceived in 1937 were lost, and many of the designers and machinists working on the project were killed. Near the end of WWII in February 1945, the United States Air Force and the British RAF bombed Dresden, creating a massive firestorm and heavily damaging the Zeiss factory in Jena. However, it was really the postwar version of the lens that really set the stage for the success of the lens. All of the optical calculations were done by hand by teams of optical technicians. It was the standard lens on the famous Kine Night-Exakta by Ihagee, the most technically advanced 35mm camera made prior to World War II.Ĭreating such a fast lens prior to WWII was one of the greatest feats in the history of optics, since it was designed and built without the use of computers. In 1927, the Biotar lens was released as a 50mm f/1.4 cinematography lens, and as 58mm f/2 version for 35mm cameras on the 19th of October, 1936. For those of you interested in lens history I recommend reading Ilya Volkov’s article Who is the father of all fast 50mm lenses? Planar vs Opic lens evolution. While Zeiss likes to claim that they were the originator of this improved Double Gauss design, there is evidence that the Biotar was based upon the Taylor, Taylor & Hobson Ltd. ![]() Virtually all of today’s fast lenses with a medium field angle (50-100mm focal length on 35mm cameras) are Double Gauss designs, like the Biotar. Furthermore, the two outer collecting lenses are each of a larger diameter than the two inner lens pairs. The asymmetry means that the front three-part lens group was overall larger than the group behind the diaphragm. These Double Gauss lenses attempted to improve on the Planar design from 1896 by abandoning the strict symmetry approach for the radii of curvature of the surfaces and the refractive indices of the glass materials, and therefore achieved additional correction parameters. Willy Walter Merté for Carl Zeiss, shortly after these earlier lenses, and all three lenses used a similar formula they were six element lenses with asymmetrical outer elements, a variant of the Double Gauss design for higher performance and increased field correction and speed. The Biotar was developed by the famous lens designer Dr. Taylor, Taylor & Hobson in the United Kingdom first developed their Panchro series, and Schneider-Krueznach independently developed their Xenon lens formula. This ancestry stretches as far back as the 1920s, a time when several lens manufacturers were attempting to improve the Carl Zeiss Planar design that originally debuted in 1896. Like many lenses, the Biotar 58mm has a long genealogy. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |