Yasuharu Mr. Yamada and Tsuyoshi Fukuda (both responsible for the 40-150mm lens design)
The Olympus 40-150mm PRO lens designers have been interview by DC.watch. There are many detailed information about the High Quality of material used by the new PRO zoom. Like Super ED lens, dual focus system and so on. And it’s also cool to see many of the pictures on DC.watch. Beside that there are also some more general info like:
2) The upcoming 300mm PRO ha a f/4.0 aperture to allow a compact size and small weight. Mobility is high on our priority list.
3) If the request is high we will make very fast primes (43rumors note: Olympus already hinted that fast primes will come in 2015)