Summary: I purchased this lens to replace another Pentax lens, the 16- 50mm DA lens which I found to be an underperformer, given its cost. The DA 17-70mm lens has performed well and is definitely an upgrade from the 16-50mm DA lens it replaced. The autofocus system does work well and only ocassionally misses its mark but is usually quick and responsive. The images this lens produces are crisp and very sharp especially when the lens is stopped down.
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: I just started to use this lens on a new camera but feel it will be in my standard setup from now on. From the start this lens is impressive for its smooth quiet operation and extra fast focus. The lens hood is a little fussy to attach but stays put and doesn't interfere with the view.
Pros: Consistent Output, Easily Interchangeable, Fast / accurate auto-focus, Great everyday lens, Great zoom range, Lightweight, Super smooth operation
Summary: I like the range and the f4 has good narrow focus range, the lens is not as sharp as the 50-135 Pentax Star lens or the Sigma 18-50mm 2.8 that said it focuses well and better than the 50-135mm. It is not super sharp at wide angle and mine is sharper at 70mm which is where I will use it the most. As my carry around general use lens it will be great, my daughter will get my Sigma 18-50mm 2.8 for her commercial work now.
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: Picked up one of these as it has a good range in terms of 35m (26-107). Also wanted to get it before pricing continued to go up up up. Harder to find this online in Canada for cheaper than $500US/700CDN. Quite solid build, and heavy! Still trying to learn how to get used to this lens as it behaves differently from my 16-45. Sharpness appears to be get better around 5.6/6.3, and solid at f8.