Well after searching for years for a Kalosat diffusion soft focus pictorial lens with no result, I finally decided to make one. I took a quartz meniscus lens of about 120mm focal length, an old lens barrel, some focusing helicoids, my camera and a dried up rose bouquet, and well, here are now some results of that contraption at various aperture settings. The lens element itself is about f4. The "diffusion" effect gets quite visible.
some crops:
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