Basic information of tiansai

The word Tiansai comes from the pronunciation of the number 4 in Greek, because the three groups of four-piece lenses announced by Zeiss company are composed of four lenses, so it has the meaning of Tiansai. At the same time, in order to distinguish it from other manufacturers' lenses that completely imitate our company's product structure, Zeiss Company gave three groups of four lenses a specific name-TESSAR. Over the years, the outstanding performance of Tiansai lens has made it still loved by photographers. Tiansai lens can still be found in the sales catalogue of mainstream photographic equipment manufacturers.

Before the large aperture Sonnar F/ 1.5 and f/2 lenses released by Zeiss in 1932, the lens-inserted cameras were the most advanced and the most expensive. At that time, the sales method generally adopted by manufacturers was that a camera had a variety of lens matching schemes according to the distinction between the market and the sales target, and the price of different lens configurations would naturally be different. Usually the preparation of the lens of the same camera is definitely the most expensive. For example, take 1928 when Zhang was killed in Huanggutun. At that time, the average annual income of Japanese employees was 3.79 million yen (about 276,679 yuan). But Ikong used 1928 and 105mm f/4.5 days lenses. The price of Reid 6×9 camera is 12 1 ten thousand yen, and the price of 105mmf/6.3 lens is 1 1 ten thousand yen. Domina 105mm f/4.5 lens with attached days is priced at 925,000 yen; Zeiss Noba 105mmf/6.3 with Kirk lens cost 790,000 yen, which should be considered extremely expensive at that time. Before World War II, a large number of cameras with sky plug lenses came out. For example, 1937, Luflex's most famous AutoMat is equipped with a 75mmf/3.5-day plug lens. At that time, the media had such an evaluation: not to mention the ingenious structural design of the Tiansai lens, but the gorgeous scenery and rich descriptive ability were not exaggerated. It can vividly reproduce the tones of black, white and gray. It is not limited to the description of Gao Fancha.

The above statement may be the author's evaluation based on his own negative film, which may not have the basis of optical test. Even so, the reproduction of black in the Tiansai lens is amazing. On the basis of the balance of black, white and gray, the maximum density of black is helpful for the lens to obtain sharp images. Tiansai lens also won the special title of "Zeiss Hawkeye".

Tiansai is regarded as the number one lens by Zeiss, and all the top cameras produced by Zeiss are equipped with Tiansai lenses. From the original monocular camera to the later folding portable film camera (that is, the eight Zeiss Icahn we are familiar with), from years of confrontation; Leica (Leica) and Contac (Contac), as well as LULAI (R0lleiflex and Ikoflex), all the advanced cameras of these brands use Tiansai lenses without exception. On the contrary, the plane lens that we admire today has disappeared for a long time in Zeiss' own camera (it was not until the appearance of SLR camera that this phenomenon was broken), which shows Zeiss' interest in it.

Although the design patent of Zeiss was very strict before, the lens with Tiansai structure can be found in the product catalogue of any manufacturer. I remember once, out of curiosity, I took a 24-inch photo of the old M39 Luokou 5 cm f/3.5 lens on a magnifying glass. The image was extremely sharp and the dark details were rich and natural. Surprised, I put it on the camera and took a group of photos, and the effect was surprisingly good. Looking through the information, it turns out that the famous Elma, which was produced by 1924, is also an out-and-out lens of the Tiansai. From Fu Lunda's Skoper Schneider191920 Xenar, Rogers Kodak 19 14 Ektar, to today's Nicole's M-series lenses, the blood of Tiansai lenses has flowed out. Due to the gluing structure of the back group of Tiansai lens, the influence of astigmatism on the overall imaging quality can not be seen in the whole picture. The unnatural feeling of the out-of-focus imaging part has also been improved. You can also see that the clarity in the picture has been greatly improved.

1940, the United States developed rare earth element glass with refractive index above 1.7. A high-quality Tiansai lens with a lens aperture of f/2.8 is manufactured. Some designers hope to develop a wide-angle lens based on this structure. However, it needs both a large-caliber standard lens and a wide angle. It is difficult to do because it is limited by the four-piece structure.

Since 1953, Japan has vigorously promoted the research of new high refractive index optical glass, and since then, the manufacturing level of lenses has been further improved. Because the refractive index of new glass is 1.6. Japan can also produce lenses with stable performance and excellent f/3.5 caliber.

The optical structure of Tiansai is simple and practical. Because of its high resolution, moderate contrast and small distortion, it soon overwhelmed all kinds of lenses before listing. And won the reputation of "Eagle Eye". Tiansai lens has been widely used in various photography industries since its launch. Different kinds of Tiansai shots can be seen in photography, printing and plate making, aviation, remake, film and other fields. Hasselblad and Lulai cameras are also equipped with a telephoto Tele-Tesar lens with variant design. Today, it is difficult to see the standard lens with Tiansai trademark on various cameras. It was concealed by more complicated lenses designed later. But in any case, it will always be a bright superstar in the minds of designers and users. It also left an indelible mark on the milestone of optics.

Zeiss once had a C/Y bayonet with Taisha 45mmf/2.8 and Kangtaishi, with a thickness of only 0.9cm and a weight of 75g, but its performance was amazing. Although the performance of three sets of three-piece Kirk lenses is much better than the previous lenses, this lens can not eliminate optical defects such as high-order aberrations other than primary aberrations. Not satisfied with the performance of three sets of three-piece Kirk lenses, designers added another lens to this lens structure to improve the overall imaging quality of the lens. As a common sense of optical design, designers all know that in order to compensate the unique aberrations of photographic lenses, it is best to adopt the symmetrical design of multiple lenses, so that the optical defects of many lenses can be offset by structural advantages. But the problem comes back. That kind of design, under the design and manufacturing conditions at that time, meant that it was impossible to be small and light. Today, as long as you open some optical books, you can often see the argument that Tiansai lenses are improved from three groups of three-piece Kirk lenses. The viewpoint of these books is that the third lens in the structure of three groups of three-piece Kirk lenses is replaced by a cemented lens, which is the shortcoming of the three groups of three-piece Kirk lenses, such as astigmatism and coma at the edge of the lens will be controlled to some extent.

In view of the above statement, in some optical books, Rudolph's Tiansai lens is considered as another system similar to Taylor's three-group three-piece Kirk lens structure. Tiansai lens is not the imitation and improvement of three sets of three-piece Kirk lenses, but the development type of Protar and Unar deformable lenses designed and manufactured based on Rudolph theory. At present, this view has prevailed.

So, which of the above two statements is more true? If we don't know the design idea and theory of Rudolf, the designer of Tiansai lens, it is difficult for us to tell the ins and outs of Tiansai lens. What kind of theoretical principle has been designed under the guidance of Tiansai lens? What other lenses are affecting the design of Tiansai lens?