Rudolph's legacy [Rapid Plasmat]
「院落」Yinraku P3 60mm f1.2
2024.11.27
The Fourth Kino-Plasmat
We have received a complaint that the name Kino Plasmat, designed by Paul Rudolph, was trademarked in 2017 (trademark registration number: No. 5985013. You can check the number on the Japan Patent Office website). We are currently requesting a reexamination to the Japan Patent Office under Article 4, Paragraph 1, No. 10 of the Trademark Act, but since it may take time or the trademark may be approved, in that case we will replace the trademark with the patent number "**DE401630**". For now, we are requesting it, so we have left it as it was. We will change it as soon as we receive a response. If we can do this, it seems that we could take over "Hugo Meyer" by trademarking it. The system for protecting our reputation is reversed. Since Plasmat alone is trademarked, we will change all of it, including Rapid, to the patent number. We apologize for the confusion and inconvenience.。- 2025.3.15
In the obituary of Paul Rudolph in the spring of 1935, it was mentioned that the last lens he worked on was the "Rapid Plasmat" (US Patent US1833593). This design was rejected by the German Patent Office. It was described in data sheet 858, which Merté had personally produced and is kept at Zeiss, and had a field angle of about 30 degrees. It was designed while he was still employed by Mayer, and it is known that Mayer sold a 12mm f1.1 for 8mm film. This is equivalent to 70mm. The patent application was approved in the United States. The aperture is described as f1, but Merté points out in the table of contents of the data sheet collection that it is actually about f1.2.
This is Kino Plasmat for small film sizes. Kino Plasmat also comes in 12.5mm for 8mm movies, but as the lens gets smaller, it loses its appeal and the film becomes smaller, resulting in poorer images, so I think they thought they had to make something specialized to make up for that. They tried to develop the best lens for commercial reasons, expecting that 8mm cameras would become more popular in the future. In that sense, it can be said to be an enhanced Kino Plasmat. The lens is small for small films, but it is well-designed, so when it is scaled up to 35mm, it becomes huge, and it becomes irrational to use a lot of heavy and expensive glass. In that sense, it is for small films. However, I experienced the greatness of Kino Plasmat, and being able to see in a larger size what I created to capture the rich, solid images in 8mm makes me want to reprint this as well.
The drawing is of the size that will actually be manufactured. You can see that the aperture does not fit all the way in. The lenses are touching (they are not touching during manufacturing). The patent description states that the aperture can only fit partway in, so it is necessary to use a modern type of rotating aperture. It also warns that the glass must not be pressed together (it will expand and crack when it gets hot). It can go up to f2.8. It is an incredible lens with f1.2 to f2.8. If you use this in broad daylight on a sunny day, you will need a very fast shutter speed, which is possible today but would have been impossible in the past. Therefore, you can see that it was not designed for use with stills. However, for movies such as 8mm, it is difficult to focus the light because of its small size, and it becomes dark. It means that it cannot be used unless it is this bright.
Please select if you would like no glass coating. Coating is an additional 11,000 yen and a minimum of 20 reservations are required.
Dedicated hood included. Filter diameter 62mm. Minimum shooting distance 0.5m. Straight helicoid. Aperture blades 12. Actual weight 567g.
The price varies depending on the number of units to be manufactured, and production will be confirmed if 25 or more units are reserved. Reservations are confirmed with full payment, and if the price drops, the difference will be refunded. Reservations will close around spring, and production will take four months, so they will be completed around summer to autumn. Since my store does not pay consumption tax, we limit annual sales. Therefore, in some cases, people who make reservations in the latter half of the year will receive their items next year. If we pay consumption tax, we will be in the red, so we need to strictly enforce it. Thank you for your cooperation.
25 ¥314,000 40 ¥225,000
30 ¥277,000 45 ¥206,000
35 ¥244,000 50 ¥194,000
There are 19 reservations, 6 of which are coated and 3 are undecided. If we reach 22, we will make 30 because there will be almost no left for 25. Reservations will close on April 6th. - 2025.2.24
Although the thickness, spacing, and lamination position of the glass are different, you can see that the lens structure is the same. The lamination is done to adjust for chromatic aberration, so its presence on other aberrations is quite limited and generally unrelated. The scale is the same, so you can see how huge and thick the Rapid glass is. It looks like it will produce a rich and dense image. Both are set to a focal length of 50mm.
The actual product is 57mm (marked as 60mm), so the glass is a little larger. The recommended length is 70mm (about 32.5 degrees angle of view) (Kino-Plasmat seems narrower), but I thought that this might be too long, so I decided to go with a 39 degree angle of view, which is about 3 degrees wider at half the angle of view.
There are two other types of Kino Plasmat, but they also have the same basic structure. According to the patent data, Kino Plasmat was the third Kino Plasmat. Rapid Plasmat was the fourth, and Dr. Rudolph's last Kino. Looking at the beauty of Kino Plasmat, it is a tragedy that the last Kino has not appeared in the world. It makes me have high expectations for how beautiful it will be.
Kino Plasmat was sharp in terms of focus. In contrast, Rapid Plasmat has a spherical aberration (left) of about -1mm, which can be considered to be in the category of soft focus (modern soft focus lenses have a more serious bokeh effect, so from that perspective it is not soft focus at all. The image is similar to Leica Summarit, which is designed to have a large aperture, and the residual aberration makes it slightly soft. It seems close if you think of it as a lens that has organized the design and made good use of that). At f1.7, the chromatic aberration disappears almost completely, but the spherical aberration is maintained up to that point, and from there the spherical aberration decreases up to f2.8, and when stopped down it becomes closer to
Super Six. The refractive index of the glasses used in Super Six is not very different, but the refractive index of the glasses used in Rapid Plasmat is the same. Both designs use only two types of glass with different dispersions. The tangential line (dotted line) in the astigmatism diagram (center) is the same as the sagittal line of Kino Plasmat, and the other line is inverted. It is aligned in the same direction as the spherical aberration. This is how we get a flat surface, but there is too much aberration, so it is not flat.
The focal width of the Kino Plasmat is narrow, but the Rapid Plasmat has a wider focal width because the glass spacing is narrowed so that the aperture does not reach the back. The glass spacing of the Kino Plasmat is wider at f1.5, so the impression is likely to change.
The aperture is specified as f1, but as Merte pointed out, f1.2 was the limit. It does not cover 44x33. It is a cylindrical giant gun with the rear lens sticking out more than 6cm near the flange. The filter diameter is 62mm (even the Summarex is 58mm), so Leica rangefinders can be used, but there is a lot of vignetting in the bottom right of the viewfinder.
The design value for the glass transmittance is 100%. Even with coating, there is a small loss, but without coating, f1.2 becomes f1.5 (labeled T1.5) with a transmittance of 72%. However, the label is left as f1.2. This is because in aperture-priority AF, the shutter speed is automatically adjusted, so there is no need to consider it, and transmittance and depth of field are unrelated, so the thinness of the focus remains f1.2. In any case, f1.2 is too bright, and even if you narrow it down, it only goes up to f2.8. Without coating, it becomes about T1.5 to 3.5, which should be easier to use. T1.5 is quite bright even at night.
Kino Plasmat has five types: f2, f1.5, Rapid f1.2, and the f2.5 described in the f2 patent is probably soft like an old Leica, and the other f1.7 is over the Rapid's under, so it would have been highly rated if it had been preserved in modern times. The aberrations of the Rapid Plasmat also start at f1.7, so f1.7 may have been an important point in terms of soft focus, which makes use of spherical aberration.
Historically, there have not been many lenses with a large aperture of f1.2. Recently, there is the SONY FE 50mm F1.2 GM, and a patent has been applied for (
JPA2022-140076). It seems that the product has been produced with slight modifications based on this data, but I don't think there are any major changes, and the patent also includes an aberration diagram, which I will post below. Please note that this is not a comparison with the Rapid Plasmaart, which is a Kino for small film sizes.
You can see that it is almost aberration-free. Recently, the trend is to use digital effects (filters) depending on the purpose. Therefore, it is important to obtain a basic image that is easy to apply effects to. On the other hand, it is also possible to use it as it is. This may be the case if you think about being able to handle anything. There are also inexpensive models available, so I think this is basically for business use. This business includes work that has become commonplace for ordinary people, such as selling goods including auctions and videos. Therefore, much of the photography work has become a business, and the number of people involved is increasing compared to before. Although I don't think it has been officially stated, it seems that recent lenses in general are designed with the assumption that effects can be used. Therefore, I think it is a similar policy to large-format lenses.
In January 2025, Instagram abolished many of the previously popular effects and also prevented users from saving customizable settings. It was no longer possible to "make it look better" in modern terms. While it is still possible to do so using other companies' apps, Meta's official stance has been to deny it. The background to this change is that in Europe and the United States, the "manufactured" aesthetic sense regarding beauty and body shape has recently been criticized as having a negative impact on young people. Plus-size models have also appeared. Since this is a story from across the ocean, there may be people who will sue in the future, so I think they abolished the excessive effects first from a compliance perspective. Looking at this trend, it is unclear how long the large-format orientation will remain the standard. However, at the same time, it is something that will never lose its necessity. For example, in architectural photography, there has long been a tilt-up, and if there was a utility pole at the best angle, it was tricked into not being visible. Today, it is digital, but this necessity has not disappeared even with the changing times.
Modern lenses are likely to change with the trends of the times, but this is a difficult change. If what Sony is making today is large format, this is just as difficult as the various large format lenses that are not simple. Although it is aberration-free, it is not completely aberration-free. That little bit is difficult, and it is not disclosed in the patent, but it is commercialized by making some changes to this aberration-free part. As with large format, there is no one that satisfies everything, so even at Sony, Zeiss designs remain and provide options. There is talk of Zeiss withdrawing from the camera lens business in general, and if that were to happen, it would be a major step back in culture. I am grateful that Sony is handling it. If it is still difficult, I would like Zeiss to remain by switching to hand-made production like Leica.
When it comes to large format, dark lenses with f4 or less are attractive. In the 19th century, there were pitch black lenses such as f32, but for some reason, lenses for dark landscapes are beautiful. In our modern concept, if you stop down too much, the image will only be hard, but this is different. Since it is open at F-number 32 or so, it has softness because it is open, but still has detail because it is f32. It has both. Leica's Hector 28mm is f6.3, but even this is enough to feel the beauty that comes from a world with little light. There seem to be a lot of people in the United States who love large format, and they must know this world. There are much brighter lenses at 28mm, but stopping down to f6.3 is no good.
So when it comes to f1.2, it's a different expression. An f1.2 lens with no aberration means that the target area is much wider than before. In that sense, it may be meaningful.
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Since 2012 Photo Cinema reproduct lens [Mu-Yichi-Kyo] is licensed under a Creative Commons 表示 4.0 日本 License.
