Już nie:
"Takahashi company, top-of-the-range manufacturer, has although decided to use ED glasses as well. Stopping the use of Fluorite, mainly for environmental reasons, didn't mean that optical performances have declined. The most obvious example is the FSQ-106ED, that can be judged by the curves of chromatic correction. The result is outstanding : the new ED formula does even better than its Fluorite ancestor ! Moreover, the correction was widened apart from the visible spectrum to adapt to the new demand of the numerical imaging."
Pojawił się też (fluorytowy):
SharpStar 100QII f/5.8 Quadruplet APO Astrograph Telescope | First Light Optics
Petzval, więc jeśli dostanie się egzemplarz sprawdzony, to może to być alternatywa (?).