DA 17-70mm f/4 on Z-1p


The "Target" images used a tripod and 2-second delay and no lenshood. No filters were used.

I used aperture priority throughout. Being an SDM-only lens, autofocus didn't work. Even using the Pentax Magnifier FB, it was hard to focus on the rather clear screen of the Z-1p. Therefore, I only used the lens on the Target, not the Wall, and I don't guarantee that I got the focusing right.

Teleconverter Focal length Target  
(None) 17 f/4 f/8  
(None) 35 f/4 f/8  
(None) 70 f/4 f/8  
1.4 (Kenko) 24 (17 on lens) f/5.6 (f/4 on camera) f/11 (f/8 on camera)  
1.4 (Kenko) 49 (35 on lens) f/5.6 (f/4 on camera) f/11 (f/8 on camera)  
1.4 (Kenko) 98 (70 on lens) f/5.6 (f/4 on camera) f/11 (f/8 on camera)  


I use this a lot in my studio, because it has the right range of focal lengths and it is capable of giving sharp results. I also use it for general photography if I am carrying around just one lens. But it will be replaced as soon as Pentax offer something equivalent but better (without its faults). I don't want to have to use two lenses, such as 18-50mm plus 50-135mm, in the studio to cover this range. I even have an FF lens that I have used for studio work in the past: the Sigma 24-70mm EX DG Macro.

So I didn't do such a comprehensive test as with some of the other lenses, because it is very unlikely I will ever want to use it on a Pentax FF camera.

This lens really is constrained to the APS-C sensor size throughout its range. But it might be usable at medium and long focal lengths with a teleconverter. (I stll expect to replace this lens sooner or later).