Autofocus very poor, A real let down compared to pre-Hoya days! Much better results with my old 28-200mm from back in the 90s. And yes it too was autofocus.

Seven months of research to decide this purchase. I am satisfied with the result so far. Silent and fast.

There are several mid range zoom lenses in the Pentax range, including this 17-70mm with a constant aperture design. Is this one of the best choices for Pentax users, or has it been overtaken by more recent lenses? Let's find out.

Very good central sharpness; Excellent central CA control; Focuses very close; QuickShift focusing available; Silent AF; Constant aperture design

Lower edge sharpness; CA at edges at 17mm; AF not the fastest; No weather resistance

All round use. Best bang for the buck. A little bulky, but to be expected.

Consistent Output; Durable; Fast / accurate auto-focus; Strong Construction

Heavy

Make it a little faster, and add weathersealing and you could put a DA* in its name and double the price. But the fact is it has the same SDM Drive system the most expensive Pentax lenses have and it just flat out is consistently better, corner to corner, than the more finicky 16-50mm DA* that can...

Consistantly excellent image quality

No weather sealing

I bought this lens as a standard zoom for the K-01 Pentax CSC. It works well with the camera with the quality I've come to expect from Pentax over the years. For those that want looks as well as capability then the combination of the lens and the new Pentax CSC is very good idea.

Consistent Output; Durable; Easily Interchangeable; IDEAL FOR K-01; Quick Focus; Rugged; Sharp Focus; Strong Construction

Fantastic lense well made good in all light levels with F4 and water resistant too :-)

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.

I have only had my 17-70 for a short time, but for now I am quite impressed. The focus is quick and silent. I have shot in some low light situations and the lens has not had any hunting issues. Sharpness is very good. So far this lens has produced gorgeous landscapes and beautiful portraits.

Pentax describes the 17-70mm f/4 lens as a "standard lens with extra zoom," a cute catch phrase. But "standard zooms," as they're called, are one of the most popular lens groups.