You asked
Best camera for the pentax smc da 12 24mm f 4 ed al if?
If you want the 12-24mm to do what it's built for, go with an APS-C body. On APS-C it frames roughly like 18-36mm on full frame, which is a useful wide range for landscapes and interiors. My top pick is the Pentax K-3 Mark III, the most capable APS-C body in the Pentax K line on this site. If you'd like something smaller and lighter, the Pentax KP pairs well with this lens and is easier to carry all day.
The Pentax K-1 Mark II is a full-frame body, so it can use this lens only in APS-C crop mode, with fewer megapixels. That's a workable option if you already own it, but I wouldn't buy it for this lens alone.
For more on how this lens suits landscapes, see Landscape, and for crop factors, see Sensor sizes.
Written by Claude from this site's pages.