![]() ![]() Even in comparison with the designs of later manufacturers, the superiority of AZUMA's design stands out, because other designs are still fundamentally Gauss-type. It is quite difficult to design a high-performance lens with a picture angle (angle of field) of more than 62 degrees as a simple Gauss-type lens.Īnd back then, it must have been astounding to produce such a large-diameter, wideangle lens. The concave lens closest to the film surface serves as a field flattener. It also provides a major improvement in correcting lateral chromatic aberration (peripheral discoloring, smear). The key feature of this lens is the cemented lens at the back.Īlso called a doublet, this cemented lens improves the spherical aberration and coma so common in high-speed lenses. ![]() The external appearance up to this point is similar to other Xenotar-type lenses, but the design utilized the totally new Lanthanum (La) -based glass convex lenses to improve spherical aberration and curvature of field, significantly enhancing both sharpness and image flatness. It is pretty clear that this is based on the symmetric lens type.įrom the left there is a convex lens, a compound convex/concave cemented lens, a diaphragm, a concave lens, convex lens, and then another convex/concave cemented lens. This discussion will be a little more difficult, but please bear with it.įirst, take a look at the cross-section of the W-NIKKOR 3.5cm f/1.8 (Fig. Structure and features of the W-NIKKOR 3.5cm f/1.8 lensĬross-section of W-Nikkor 3.5cm f/1.8 lens To be a lens designer back then required enormous determination and devotion. a staggering amount of computation and time must have been needed. It took another one to five years for competitors such as Ernst Leitz to develop similar lenses.Īt that time, the tools of the designer were the abacus and the logarithmic table. patent in 1959, signifying general recognition that this was indeed a new type of lens.Īt that time, most 3.5cm lenses were in the f/3.5 to f/2.5 range, and this was the first lens of f/2 or faster in the world. He filed the patent application for the large-diameter, wideangle lens in 1956, and was granted the U.S. This expert Japanese designer is little-known outside the industry, but his achievements can be traced through his countless reports and patents. Ludwig BERTELE was also active in the field in Germany. ![]() He made an enormous contribution to improving Nikkor lenses, especially in laying the foundation for aberration balancing.Īt the time he was active in the field, Dr. The optics were designed by Senior Manager AZUMA, Hideo of the Optical Design Section, and the design was completed in the winter of 1955.Īzuma was one of the teachers of WAKIMOTO, Zenji (mentioned in the first tale), and had extensive experience in designing "S" / "L"-mount Nikkor lenses. The body associated with it was the Nikon S2, but this was followed by the SP the following year, then the S3 the next, so you should understand that it was developed to match the concepts and designs of the SP and S3 as well. This lens, first released in September 1956, is the brightest wideangle lens in the world. The third tale discusses the W-NIKKOR 3.5cm f/1.8, our "S" / "L"-mount interchangeable lenses. Symmetric high-speed, wide-angle lens W-Nikkor 3.5cm F1.8 ![]()
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