Very interesting to hear from someone who has owned all 3!
I dont mind doing a bit of cropping with the 10mpix k10D, so above 14mm is not that much of a problem. The widest I have now is an 18-50 zoom that I basically use as an 18mm prime and I rarely find myself zooming in with it, but often find myself wanting to zoom out more but of course not being able to.
I think its a bigger issue loosing those 2 extra mm on the wide end, because you cant recreate those by cropping
You can foot-zoom but I often find myself pressing myself up against a wall that is stopping me from backing up further.
The zoom certainly is very good in terms of distortion and sharpness.
But I am actually not that sure if it will beat the 21mm, even tho the distortion of the latter is a bit too much. Because in my experience the zoom will not perform as well at the long end of its range. And this was confirmed by klaus' test over at photozone.de where he not only mentioned lower sharpness but also loss of contrast and recommended that the zoom be stopped down an extra stop. That brings it to f5.6 which is very slow.
Of course one alternative is to get a zoom in place of the da21, if you got the new 16-50 f2.8 da zoom then that should beat both lenses at 21mm and will go down to 16, where the da 14 will extend it for that extra wideness and you can enjoy the same f2.8 max aperature.
I think this is the thoughest range to choose lenses for pentax, and as if the difficulty was not eanough, there is the risk of Pentax releasing an > APS-C sensor camera and thus you cant keep your wide lenses if you upgrade.
Speaking for the DA 14 is also the close focusing distance, this is very usefull for dramatic wide angle closeup shots. Also the build quality of the DA14 seems very very good, I wish petnax would use the same kind of wider focusing ring on its other primes, and not place it at the end of the lens barrel like with the FA 35, 50, 100, etc.
Originally posted by GaryML I current have the DA 12-24mm and previously owned the DA 14mm and the DA 21mm. I went with the DA 12-24 for the convenience of the zoom and to reduce the number of lenses I need to carry. For my style of photography (landscapes), the zoom is very useful for cropping out distracting clutter from the corners of a scene and adjusting the composition where my movement may be restricted.
The DA 12-24 has excellent sharpness and very low geometric distortion. It matches the DA 14 in terms of sharpness and correction (even at 12mm), and the performance gets even better at the longer focal lengths. I believe it has less barrel distortion than the DA 21 at 21mm. Both the DA 14 and the DA 12-24 should be well stopped down for the sharpest image. Also note that the DA 14 will focus closer than the DA 12-24.
The weaknesses of the DA 12-24 are greater chromatic aberation and slower speed. There is noticably more CA as compared to the DA 14 and much more than than the DA 21. This is visible in certain shots as purple and green fringes at high contrast transitions (e.g., tree branches against a bright sky). For critical prints, you must use a software tool to correct this. (If you shoot RAW, the Pentax Photo Lab does a fine job correcting the CA and it only takes a minute. Adobe Photoshop, Elements or Lightroom can also correct this in RAW or .jpeg files in less than a minute.) The DA 12-24 is also slower: one full stop slower than the DA 14 and about 2/3 of a stop slower than the DA 21. It does have some small effect on the viewfinder image, but it is not an issue for me since I use it about 98% of the time for outdoor scenic shots.
The DA 12-24, DA 14 and DA 21 are all excellent lenses and I had a hard choice deciding to keep the zoom rather than the DA 14 and DA 21. In terms of ultimate image quality, the DA 14 and DA 21 are probably better than the zoom. But for my specific needs, the zoom was the better choice.