I had the 18-135 with the K-30. It was ok. Took some great shots with it. Wasn't 100% satisfied. When I had the money bought the K3. They made a good hiking and walk around pair. Better than with the K-30. Now I have the KP, seems better to me. The difference isn't only image quality (my niece has the K-30 now with the DA 50 1.8 and has great results), but more consistent autofocus too. The 18-135 is very convenient especially for some type of photography. It has its compromises. Same goes to the 18-55. Although the 18-135 is better. My point is that the 18-135 should be better with your K-70 than on your K-30, I think. At least in autofocus. Sigma and Tamron have good lens in the 18-55 range. I got the 20-40 during this years Pentax Black Friday/cybermonday extravaganza and it's looking good!
Last edited by Caribe; 12-30-2018 at 07:12 AM.