Originally posted by RockvilleBob Another issue is the mystical FF Pentax plans to introduce. I could not buy the 560 until the next generation of pentax cameras are introduced.
I guess it doesn't make it easier for Pentax to sell the 560mm when they leave their exclusive APSC orientation. However, with a FF camera in crop mode, you would still have the best of this lens, similar to an APSC camera. If Pentax release a 36mp FF camera, you could still end up with at least 20 high quality mp's. And less need for coupling a teleconverter. I think Pentax should offer multiple crop modes on their FF camera, and implement them well. Alternatively, you could crop yourself. Canon is still at 22mp, so with the high quality 36mp Sony sensor, I still see use for the 560mm. 36mp Full frame in crop mode will probably beat lens + TC for IQ.
Not that I would buy one myself though, I settled for a used Sigma 500/4.5. But if the 560mm is a really good lens, I might watch out for a used copy in the (far) future.
Chris