The name “Tieguanyin Cannon†was also given by my friend (see the first article in the series). Why was there such a name? Because the lens body of this lens was processed with Tieguanyin tea cans. Made! Don't be surprised at first, let me slowly say the story of this lens. Rodenstock Rodenstock is also considered to be a well-known brand in the German optical industry. The predecessor of the company was ZEISS's foundry. Therefore, on the optical path, it also inherited the bright colors of Zeiss's fast and rich. Afterwards, Roden took over and focused on the lens aspect of the large/medium format, which is still the main lens supplier for Hasselblad cameras. Roland's lens on hand is not too few, including the Mirror Lens Rodenstock Heligon 50mm/f2.0 in the 135 lens system, this lens has left to use for filming, but also to help friends to change to micro-single use... ...but what I'm talking about today is Rodenstock Rotelar 400mm F6. Rotelar is a Rodon telephoto lens design, using four 2-group structure, the prototype is the 1905 Emil Busch Bis-Telar f8, but the conventional design is generally 135-frame equivalent 85 ~ 135mm focal length, even for large format use Mostly only to the 360mm focal length. However, the protagonist we are going to talk about today has a focal length of 400mm, and it is a f6 aperture (relative to the telephoto lens of the same period). It is really attractive, so it is decisively picked up! Later, when the data was searched, it was found that there was such a shell on the outside that matched the thread on the mirror to achieve precise focusing. But general industrial lenses do not have such a delicate structure, and the focal length and aperture will not be the same, so it is inferred that there should be other uses ... One of the inferences is that the aerial lens used on the plane, because it really needs Combination of ultra-long focal length and large aperture. But when this lens arrived, it still made me startle! That's right, this is a guy with an caliber up to 82mm, with almost the same size of the front and rear lenses. Of course, the weight is also amazing. It's 1292g...2.5 pounds, but it also doesn't have an aperture and focusing mechanism! So how can such a big guy be used as a normal lens? At the time, I didn't have a clue. The first step in changing the lens is to determine the flange distance. However, the general lens can easily measure the approximate data with light and white card because of the short flange distance. The focal length of this lens is so long, and the front and rear lens groups are almost equal, which means that the ratio of the object distance to the flange distance will be relatively close to ... 400mm focal length of the object will not be within a few meters, so the law Lan distance may go to tens or even hundreds of centimeters. As a result, the commonly used methods are difficult to be effective, and you must first find an object that can replace the lens body and use the focusing bucket to make actual measurements. That's right, so I took a Tieguanyin tea bucket as a temporary substitute. There is only one picture left, but it is missing. I am afraid that this article will be thrown eggs. With the tea bucket, let me figure out the flange distance of this lens and also understand its imaging effect. The imaging effect is of course not comparable to modern lenses, but at least it can be seen... It is necessary to know that the inner wall of the tea bucket is not dulled, and the narrowing of the lens body does not conform to the light path structure, but at least from the test shot photos There is the potential for continued transformation. The next step is to start designing the real lens body. The first consideration was to find lathes that were machined from aluminum or copper. This is a drawing designed at the time. In order to take care of the integrity of the light path, the entire structure is rather complex and requires a lot of cutting with a single piece of material, so the cost will be very high. He had tangled up for more than half a month and had communicated several times with the masters of several lathe processing workshops. Drawings were constantly changed and changed, but no suitable solution was found. But in the end I still thought of a "bad idea"... Deng Deng ~! Black steel guns appeared ~! The metal parts used to modify the lens body are actually aluminum screw shades. I have used five different calibers together in series. Not only does I have to meet the flange distance required by the lens, but also the rear mouth is the M42 screw. , You can easily connect the focusing barrel or close-up skin cavity. And the advantage of using a hood is that the interior has been made a step-like extinction pattern, with the oxidation of black process, incidentally to eliminate the problem between the mirror is also solved. Afterwards, only the canon XXB's tripod tripod was placed on the second section of the mirror body. This way, when the lens is mounted on the NEX5, it can just reach the front and rear weight balance. However, after this conversion, the weight of the lens reached 1560g. Then, Manfrotto's three-axis head, heavy-duty tripod, and camera were included. The weight of the full set of heads exceeds 10kg. Therefore, in addition to the daily use of Lotus in the daily routine, the basic is rarely to go out with this equipment. Of course, what everyone cares more about is the quality of this lens? The above two photographs were taken under sunlight and shadow respectively. It can be seen that the imaging of the lens is not sharp, even some "meat", but the color is very beautiful, vivid and saturated, the transition is natural and smooth, and the bokeh is with A faint blues is a typical German style. Under strong light sources, the anti-glare capability of the lens is not very good, but when shooting some relatively clean scenes, the subject that is slightly dizzy will have a similar artistic mood. Of course, I also use it to shoot the moon (NEX 5, the original image without crop), the 400mm focal length is equivalent to 600mm in the APS-C frame, but still not enough to let the moon hold the entire picture, and in such an ultra-long focal With support, the moon runs really fast! Some people may ask, even if the colors are very good and very edgy, but there are still gaps compared to the modern lens, there is no need to toss this way ... In fact, this is a personal choice, some people like to constantly pat, there are also People like to collect and experience various top-level equipment... And I prefer to toss these other people's eyes off, but they can have fun and a sense of accomplishment in the process of “selecting, exploring, transforming, and completingâ€. Kosta Small Power Generator,Home Use Power Generator,Kosta Air Cooled Portable Diesel Generaor,Kosta Small Power Generator Set Shanghai Kosta Electric Co., Ltd. , https://www.generatorkosta.com
