Originally posted by Rondec The results seem pretty decent with the DA 560. It is pretty expensive, but lighter than a lot of the other options out there and pretty usable wide open.
The value of the DA560 is questionable, compared to a 400 f5.6 (420 f5.6), it is no brighter, costs and weights 3 times more, and is twice longer than a 300 f4 + 1.4 TC / 70-200 + 2xTC combo.
With a good 400m prime with a bit better approaching conditions/skill, perhaps the result is equivalent to using a DA560. Anyway, for birding in the wild without hiding/strategy you need 1200mm focal length...
The other risk that I can imagine regarding the DA560 is that there might be a DFA600 to go with the Pentax FF and complete the DFA lineup in a couple of years, thus making the DA560 irrelevant.