Auch für das 300mm findet sich: "Dichtungen gegen Staub und Feuchtigkeit".
https://www.ricoh-imaging.de/de/k-bajon ... F-SDM.htmlhttps://star-lens.ricoh-imaging.eu/"To be designated as a Star-series product, a lens must demonstrate extremely high resolving power and contrast — from the center of the image field to the edges, even at open aperture — and exceptional optical performance with minimal distortion and color bleeding. In addition, it must be a very bright lens with one of the largest open apertures in its class. It must provide extreme strength, superior dustproof and weather-resistant performance, and outstanding operability. Only when all these requirements are satisfied, it is named a Star-series lens because it incorporates the very best of our state-of-the-art technologies that optimize the photographer's creative freedom."
DA* 55mm und DA* 300mm, sind Beide gelistet. Ich würde es aber nicht übertreiben mit dem "Beschmutzen".