Rudolph's legacy [Rapid Plasmat]
「院落」Yinraku P3 60mm f1.2
2024.11.27
Rudolph's posthumous work that was never produced
In the 19th century, photographic lenses were broadly divided into two types: portrait and landscape. They were expensive, so they were used for commercial purposes. I think that such specialized lenses are rather unusual in modern times. For landscapes, you can take them by narrowing the aperture, so you don't need a dedicated lens, and if you are particular about it, there are medium and large formats. There is also little sense of seeking flavor. Portrait lenses have come to be used for movies as well, but movie lenses are no longer necessarily strongly conscious of portraits. Digital effects are also possible, so it seems that the emphasis is on taking solid photos. When Paul Rudolph designed the Kino Plasmat, movie lenses were first specialized for people, and then the feeling that you could take a picture by narrowing the aperture. When you watch early movies, you can feel that the depiction is very stiff, so it is natural to think of overcoming that. So soft focus became necessary, and there are several ways to do it. One of these is the use of color bleeding by increasing chromatic aberration, and it evolved from Nicolas Perscheid for portraits to Speed Panchro for film. However, it is complicated because it is not expressed only by chromatic aberration. Kino Plasmat uses astigmatism to create bokeh, and all of these lenses use a fairly strong effect, but these lenses are no longer made today. Furthermore, over or under spherical aberration gives a different impression, but this also produces a soft effect, and what is imagined as soft focus today is under-corrected. A famous example is the Bess Tan lens, but perhaps this is no longer in demand, and there aren't many soft focus lenses on the market. They also give a negative impression, as if they are a kind of hidden weapon.
Please select if you would like no glass coating.
Dedicated hood included. Filter diameter 62mm. Minimum shooting distance 0.5m. Straight helicoid. Aperture blades 12. Actual weight 567g.
So what was Rudolf's last work, the Rapid Plasmat (US Patent
US1833593), which was not manufactured at the time? First of all, the spherical aberration is under-corrected. There is also a lot of astigmatism and a large curvature. If it was only under-corrected, it would normally become soft, which is certainly possible, but since there are various biases, it does not seem to be what we imagine simply. It has changed a little from the Kino-Plasmat, but in the end it seems to be largely the same. Although the Kino-Plasmat has a larger aperture, the expression has progressed further, and there must have been repeated research and prototypes, so it seems that it was applied for a patent with confidence and that it was for the final film portrait that Rudolf thought of.
The aperture is specified as f1, but even the calculated design value is not that large. f1.2 was the limit. The focal length is 57mm, and the angle of view is 39 degrees. If it were 50mm, the image plane would be distorted, so a 42 degree angle of view would be sufficient (usually about 45 degrees is needed). Therefore, the corners will be about 1.5 degrees narrower. For ease of understanding, the focal length will be written as 60mm. It does not cover 44x33. It is a cylindrical giant gun with the rear lens sticking out more than 6cm at the flange. The filter diameter is 62mm (even the Summarex is 58mm), so Leica rangefinders can be used, but there will be a lot of vignetting in the bottom right corner of the viewfinder.
Kino-Plasmato 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. It's a radical
Super Six. If you pursue the ultimate, you'll end up going that way. The refractive index of the glasses used in the Super Six doesn't change much, but the refractive index of the glasses used in the Rapid Plasmato is the same. Both designs use only two types of glass with different dispersions. It's frankly transparent.
You can see that the aperture does not fit all the way in. The lenses are touching. The patent explains that the aperture can only fit partway in, so a modern type of rotating aperture must be used. It also warns that the glass must not be pressed. Up to f2.8 is possible. This is an incredible lens with an f1.2 to f2.8 aperture. However, for this lens, f2.8 becomes quite normal (although it does not seem to be normal by general standards). So it seems that they decided that it was okay.
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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.
