Originally posted by WideOpen Sorry if this has been addressed to death already.
The DA* "normal" lens should be Pentax's (and every manufacturer's) flagship lens. It is a lens that can be used for 80 - 90% of applications. Unfortunately, the DA* 16-50mm is not that lens. While it's optical performance is average, perhaps adequate (though not at that price), its motor failure issues are a huge red flag for me, and why I have not purchased one to date. I suspect that any serious, professional photographer would builds their kit around a manufacturer's very best "normal" zoom lens. You can make as many class-leading APS-C DSLRs as you like (see, e.g., K10d, K5), but without that foundational lens you cannot attract a serious-enough following. In my opinion, it has been a major shortcoming of the Pentax DSLR brand.
The next DA* "normal" zoom cannot come soon enough. In my opinion, given the state of sensors, it need not be a constant f/2.8. It could be a constant f/3.5 or f/4, with a DC or the most reliable motor available, as well as screw dive in case of failure. Also, it need not extend to 16mm - too many sacrifices with such extremes. I'd be happy with a nominal 18-85mm, f/4 (actually, say 20 - 80mm) that was a real and even performer across the whole range. Heck, I'd actually be happy with a 20 - 50 mm, f/4! Just something that delivers and is reliable.
Pentax, can you deliver on the next DA* normal lens?
A million times this. The DA* 16-50mm has very mediocre IQ, and at it's current price it's a complete joke. The
Sigma 17-50mm is significantly better optically in every single way, especially sharpness and chromatic abberation, and it is half the price. The quality control issues are huge -- the one I purchased not only had had its SDM failed (it wasn't even being used; was just sitting on a shelf for a year or two) -- but even worse IQ than I epected; at 50mm f/2.8 in particular, it was complete soup across the frame, and that is no exaggeration. It's laughable that they don't have a standard zoom with acceptable IQ.
People will say "every system has some good lenses, and some bad lenses" but IMO Pentax's current lens lineup is a major, major turn off for any potential customer. I'd also mention that every single weather sealed DA lens is crap compared to other offers in the same price range; the only weather sealed lenses with acceptable image quality for the money are the DA* telephotos and telephoto zooms, and the WR Macro.