Originally posted by nicholas411 G'Day Nic,
I can't comment on film, but noticed that the Zeiss Distagon T* 1,4/35mm was mentioned by another forum member.
The Zeiss Distagon T* 1,4/35mm is only available in ZE (Canon) and ZF/ZF2 (Nikon) mounts and was never made in Pentax K mount. The Zeiss Distagon T* 2/35mm certainly was made in ZK mount and as an owner of one of those lenses I can say it is a wonderful lens and agree with Ratcheteer; you won't be disappointed.
The Zeiss Planar T* 1,4/50mm and Makro Planar T* 2/50mm were both made in ZK mount. If this focal length interests you there is likely to be a couple of 1.4/50 ZK's that will come up on ebay each year, maybe one 2/50 ZK, if you're lucky. I have the 2/50, it is a brilliant lens and again, you won't be disappointed if you wait out for one. Just don't hold your breath.
From the other comments there seems to be some options to pursue with film and certainly these are cheaper options to try. If you are still interested in a Zeiss lens in K mount the 2/35 is the most likely option to be available now as there's usually some for sale on ebay regularly.
beyond this there is also another option to consider that became available a couple of months ago. The Leitax team recently introduced a K mount conversion for the Nikon mount Zeiss ZF/ZF2 lenses (it also works with other manual Nikon lenses too). This opens up options and means you can look at both of the Zeiss 35mm and 50mm options. This even includes the latest Zeiss Milvus weather sealed lenses.
The link to the Leitax website is here:
Nikon and Zeiss ZF lenses for Pentax cameras Check out this thread for some of the experiences of forum members who've fitted the Leitax ZF to K mount adaptors:
https://www.pentaxforums.com/forums/122-lens-clubs/227446-carl-zeiss-t-zk-mou...ro-planar.html
Good luck with it mate.
Tas