Originally posted by LensBeginner ...you are devious! good joke though!
:-) the DA560 kinda was removed from stock, could be a sign that the telescope design shall be replaced by a 600 prime shorter in length, and sharper than the 150-600 of Tamron. In the market, there are only 3 solutions for 400mm f5.6 light weight primes: Nikkor 300 f4 + TC, Pentax DA300 f4 + TC, and Canon 400 f5.6, all other solutions are either zooms or heavy expensive primes from Canon and Nikon.
---------- Post added 22-10-17 at 19:14 ----------
By the way, what does prevent Ricoh to make a dedicated speed booster to adapt DFA lenses to crop cameras?