Most people here probably know that many Pentax lenses are developed by, or with, Tokina. That seems to be the case for the 12-24/f4, which is sold by Tokina for other brands, but by Pentax if you want the Pentax mount.
Except that... I just bought one branded Samsung. It appears to be identical except the green decorative line next to the zoom ring has been changed to blue. And... around the front element it is marked as Shneider-Kreuznach! How do they get into the deal?
In any case, Pentax-Tokina-Samsung-Schneider-Kreuznach appear to have made a nice lens
