NIKKOR - The Thousand and One Nights No.25

Ai Micro Nikkor 55mm F2.8 (First Part)

Tonight, I'd like to answer your request for a tale about Micro NIKKOR. Micro NIKKOR is one of the most important lenses in the history of development of NIKKOR lenses. How was Micro NIKKOR born ? Why was it named Micro ? Who developed it ? So many stories, one night won't be enough. So, I will make an exception and narrate one tale tonight and another one the next night. First, tonight's tale is the story of the birth of Micro NIKKOR. Then, the next night, I'd like to talk about the progress of the development of Ai Micro NIKKOR 55mm f/2.8 and the imaging characteristics. Don't miss it !

by Haruo Sato

I. Macro and Micro

The term "macro lens" refers to a publicly recognized generic name for lenses intended for close-up photography. But, how about the term "micro lens" ? Which term is scientifically acceptable, macro or micro ? Why did the developers in those days prefix the close-up lenses with the term "micro" ? In this episode, we will see the professional spirit of the developers who put a premium on strictness.

The classical definition of macrophotography is photography of a subject where the image is recorded on film in the same or larger than actual size.

This means that macro lenses refer to the enlargement optical system similar to microscopes. However, the close-up lenses available in the days of S-type cameras provided a reduction optical system, at best involving a magnification from 1/2 to life size. Therefore, those close-up lenses were not classified as macro lenses (an optical system allowing photography at a life-size or larger magnification). In those days, Nikon had already developed and marketed superior enlargement optical systems (microscopes, etc.). The developers intended to make a clear and exact distinction. They preferred a strict definition and refused to attach greater importance to ease of marketing.

II. Development of Micro NIKKOR Facilitated by Kanji (Chinese characters)

Microphotography was associated with so-called duplication or reduction. In Japan, immediately after the Pacific War, the United States introduced a high-tech micro file system in order to store valuable historical materials and documents. However, the optical components in the system offered larger f-numbers and insufficient resolving power. Why was such incomplete system in widespread use across the United States ? This was due to the difference between writing systems (characters). In the United States, the system was required to accurately discriminate between the lower-case alphabet letters "e" and "c." Therefore, the system was somewhat practical even if the reduction of the English language newspapers was at the resolution limit. For comparison, the lenses by German manufacturers reportedly provided higher resolving power; in my estimation, their higher resolving power may have been due to the need to discriminate the umlaut (ä ö ü) and other German-specific diacritical marks. In practice, however, the system could not resolve Kanji characters. The Kanji characters used in those days had a larger number of strokes and required a resolving power several times higher than that needed for the letters of the alphabet for accurate identification.

Culture is always interesting. We, Asian people, are said to have good eyesight and thus be suited for exacting tasks by nature. This may be attributed to the elaborate composition of Kanji characters. I cannot emphasize too much that the Japanese culture and Japanese characters have been the source of Micro NIKKOR.

Under the environment and circumstances embracing Japan in those days, as mentioned above, a preliminary study was launched with the cooperation between the government and the private sector.

The development of Micro NIKKOR was then started officially as requested by Koana, who was a Professor at the Faculty of Science, the University of Tokyo. The great difficulties our predecessors faced came from the Japanese culture involving Kanji. After repeated trial and error in designing with two test productions, Micro NIKKOR 5cm f/3.5 was completed. Professor Koana shot all of a 70-pages story book "Takekurabe" by Ichiyo Higuchi with the completed Micro NIKKOR and stored the shots in a single micro card, which astonished the public. At this moment, the anecdote about Takekurabe demonstrating the excellence of Micro NIKKOR was born.

III. Progress of the Development of Micro NIKKOR

In response to the request by Professor Koana, Mr. Azuma and Mr. Wakimoto embarked on the development of Micro NIKKOR. Mr. Azuma was a schoolmate of Professor Koana. In addition, Mr. Wakimoto had studied under Professor Koana. It was self-evident that Mr. Azuma and Mr. Wakimoto would do their best. Ultimately, in 1956, the Micro Nikkor 5cm f/3.5 for S-type camera was released. This lens was an original Xenotar type. Mr. Azuma was responsible for the products. In my research, it was not sure who was the chief designer, Mr. Azuma or Mr. Wakimoto. In those days, however, the persons in charge of products were responsible for finishing the optical design as a rule, therefore, it is very likely that Mr. Azuma was responsible for the design. At any rate, it is estimated that they worked jointly.

Then time passed and the age of Nikon F began. Mr. Wakimoto redesigned the very popular Micro NIKKOR for S-type cameras, with an extended back focus distance. As a result, Micro NIKKOR 55mm f/3.5 was born with a focal length increased by 5mm, helping Micro NIKKOR to firmly establish its reputation. In 1961, the manual-type lens was introduced allowing shooting at a magnification of up to life size with the single-unit lens barrel. In 1963, Micro NIKKOR Auto 55mm f/3.5 came out with an unchanged optical system, a lens unit maximum magnification limited to 1/2x, and automatic aperture control. This Micro Nikkor 55mm f/3.5 had been well received without any change to the basic design of the optical system for about 19 years, until the Ai Micro Nikkor 55mm f/2.8 went on sale.

The successful commercialization of this lens led to stronger ties between Mr. Wakimoto and Professor Koana. Professor Koana had been engaged in the study of test charts for the resolving power of various photographic lenses and objective lenses. The task confronting Professor Koana was the development of an original chart.

However, even if an original chart was made with the aid of the photomechanical process, there was no lens available for practical use. The test chart was intended for the evaluation of high-performance lenses; this means that the lens used to develop the chart needed to be far superior to the lenses to be tested in ensuring the sharpness of images. Consequently, Professor Koana asked Mr. Wakimoto to develop the ultra Micro NIKKOR which would provide a resolving power as close as possible to the theoretical resolving power. This led to the birth of the ultra Micro NIKKOR. In addition, the experience gained in its development helped Nikon to open up new horizons.

That's all for tonight. Next night, I'll talk about Ai Micro Nikkor 55mm f/2.8. What kind of pictures does the lens provide ? What is the key to the rendering characteristics ? Who designed the lens ? Don't miss next night's installment.

Visionary Macro NIKKOR

I've been asked by some users "Why there is no Macro NIKKOR available despite the existence of Micro NIKKOR ?" Yes, Macro NIKKOR does exist. Let's take a look at the background in development of Macro NIKKOR.

To tell the truth, in parallel with the development of Micro NIKKOR for F, the Microscope Division in those days was also implementing a program for the development of a macrophotography system. This development led to the large-scale macrophotography system (MULTIPHOTO). Product development without any design compromise is Nikon's tradition. The program evolved into the large-format camera (photography system). During the development, several Macro NIKKOR lenses were born.

In addition, the Camera Division in those days had drafted a plan for the development of 35mm format Macro NIKKOR lenses. Three types of Macro NIKKOR lenses with different specifications were designed and prototyped. Their optical performance was reportedly satisfactory. However, the Microscope Division in those days (at Nippon Kogaku) had already projected a plan for a full-scale macrophotography system, thus, unfortunately, no F-mount bellows-compatible Macro NIKKOR was commercialized. However, the Macro NIKKOR evolved into Printing-Nikkor for office and industrial use, and Apochromat Macro NIKKOR for large-format cameras for photography. At any rate, the Macro NIKKOR provided the ultimate form of high-resolution optical system.