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.
|Black on White by RaVN11|
|Hummingbird and Bee by dibilio57|
from A Big Year - birds
|xheneta iseni _for DPReview by Mike Slade|
from - My Fair Lady - (Portraits in Full Colours Only + A Border)