Excerpt: I use this lens for most of my photo work. If I could only have one lens this would be it and I'd still be happy. It focuses close, great color and very sharp. I wish it was weather proof and yes I have used it the rain.
Pros: Durable, Easy to Install, Easy to Use, Good Range, Safe, Very sharp, Well Designed
Excerpt: This is my do everything lens, my work horse. Don't let people tell you that you need f2.8 you don't f4 is fast enough, and range makes it more useable. This lens makes beautiful flower pictures and portraits. It's great for weddings indoor and outdoor.
Pros: Consistent Output, Durable, Easily Interchangeable, Good walking around lens, Quick Focus, Rugged, Sharp Focus, Strong Construction
Summary: The Pentax DA 17-70mm f/4.0 AL(IF)SDM lens is a better replacement for the standard kit lens. It has a wider range of focal length 25-105mm equivalent in 35mm film terms which provides everything from wide angle to moderate telephoto. It also has a wider aperture of f/4 throughout the range. It is a very sharp lens, almost as good as the more expensive DA*16-50mm and if anything better at wide angle. It is also smaller and lighter.
Summary: Bought as am "everyday" lens for a K30. The range is perfect ( approx.26 -105mm in old money) for the great majority of the shots I take and I therefore chose this lens over the 18-135 feeling that the loss of far end telephoto was a worthwhile trade off against the mixed reviews that that lens has received. Great build quality, pin sharp images and great colour rendition.
Summary: This lens has a very versatile range, from 17-70. You may be put off by the f4 aperture, but it is pin sharp wide open, unlike the sigma 17-70 at f2.8 which is sloppy and soft. It has some weather sealing, not for storms but for light rain it will be sealed. The mfd is quite small which is nice and it is sharp at all focal length, I have taken lots of great macros and landscapes with this lens. The price has been cut so it's a bargain.