Originally posted by Digitalis Though the K24 has an uncommon 52mm filter thread (which the K50mm f/1.2 has) is a bit mystifying.
The other quality prime option at around 24mm, the ZK 25/2.8, has a 58mm thread.
I believe that Pentax would have liked to have designed the K24/2.8 for a 49mm thread,
since they always listed it in with the M lenses that standardized on 49mm,
but I suspect that it just wasn't possible given the size of the front element.
---------- Post added 12-13-14 at 10:37 PM ----------
Originally posted by mechmike10 I don't realistically expect to see Pentax build such a lens because it would certainly cannibalize sales of the more expensive lens.
Well, Pentax has done cheapo versions at 35mm and 50mm,
but I don't think those lenses are cannibalizing the DA 35 Ltd or DA*55.