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: Has hardly been off my K7 since I bought it. The long end is especially nice. It could be a tad sharper at the long end, but only in comparison to my old 85mm f1.8. Very low distortion and performs really well in backlit situations. Seems to be very solid mechanically.
Pros: Constant aperture, Flare performance, well made, Zoom range
Excerpt: I am a very amature photographer. I needed a versatile lens for close up and telephoto scenes. This lens takes sharp pictures, is easy to use, is not very heavy and travels well. The DA 17-70 mm does it all well. The price is a bit steep but the I'm happy I bought it.
Excerpt: Coming from the DA*16-50 which I found to be too big for a general walk-about lens I find the DA17-70 to be a nive lens. The filter size matched my DA*60-250 so the DA17-70 pairs up really good with the DA*60-250. Now just add a low light lens and a macro lens the kit will cover about anything.
Pros: Consistent Output, Durable, Easily Interchangeable, Fast / accurate auto-focus, Lightweight, Rugged, Strong Construction
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.
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.
Excerpt: I bought this lens as an upgrade to my 16-45mm f/4 lens. The older 16-45mm lens has excellent sharpness, contrast and color reproduction, but lacks in build quality and under certain conditions shows significant color fringing. To my delight the 17-70mm equals or betters its older cousin in all optical categories, even with its extended zoom range. Also, the build quality is excellent and the color fringing is much better controlled.
Pros: Consistent Output, Durable, Easily Interchangeable, Sharp Focus, Strong Construction