Originally posted by raider I am also contemplating to get the DA 14/f2.8...however, the DA 16-45/f4 is about 40% cheaper. Is the extra 2mm and smaller f-stop from the DA 14/f2.8 going to make much of a difference in actual photo shooting?
I presently use a DA 12-24mm, and I have owned both the DA 14mm and the DA 16-45mm.
Yes, the difference between 16mm and 14mm is quite noticeable. With the right subject, the wider field of view of the 14mm can make a difference. The one extra stop of light of the DA 14mm doesn't really make much of a difference in the viewfinder image, but it can help a bit in critical focusing.
To summarize the differences:
DA 12-24mm: Very low geometric distortion across the zoom range, but the most CA in certain scenes with strong contrast. The flexibility of the zoom more than makes up for the CA (which can be easily fixed before printing). Best when well stopped down (as is true with all of the wide angle lenses).
DA 14mm: Very low geometric distortion, excellent build quality, and closer focusing as compared to the 12-24. Less CA than the 12-24 but still visible in certain scenes. One stop faster but still must be well stopped down for best results.
DA 16-45mm: Visible barrel distortion at the wide end. In some shots I needed to correct the lens distortion (but easy to do with RAW files using the Pentax Photo Lab or similar software). Less CA than the ultra-wides, but still visible in some shots with strong contrast (also easy to fix). The wide end just barely reaches into the ultra-wide range but the flexibility of the zoom makes it a very useful lens. I liked the handling and light weight of the lens, and was never limited by the f4 maximum aperture. If you want a wide to normal zoom then this is an excellent choice and an improvement over the kit lens in several respects (wider wide end, faster at the long end, and better image quality). If your main interest is to go ultra-wide, then you should go for the DA 14 or the DA 12-24 and really experience ultra-wide.