Canon FL 300mm lens
... that the Canon FL 300mm lens was the first to use synthetic fluorite crystals in its lens elements?
... that the <b id="mwAyA"><a href="./Canon_FL_300mm_lens" id="mwAyE" rel="mw:WikiLink" title="Canon FL 300mm lens">Canon FL 300mm lens</a></b> was the first to use synthetic <a href="./Fluorite" id="mwAyI" rel="mw:WikiLink" title="Fluorite">fluorite</a> crystals in its lens elements?