Pentax does not currently sell any TCs. However, the lens road map they published last year listed a 1.4 TC. It might be worth waiting to see if Pentax releases it.
I have been looking forward to it to pair with a 300 f/4 lens. But I don't have any information about which lens the new TC will support.
|DSC_9643 by NOWHITELENS|
from Best Photo of the Week
|Thailand Sunrise by ozziebadger|
from Ships and Boats