Originally posted by Neducati Pentax 16-45mm F4
Pentax 16-50mm F2.8
Pentax 17-70mm F4
Sigma 17-70mm F2.8
Welcome to the forums!
Your question is very common, and I have the impression nearly all users with the original kit lens go thru this.
First of all, in case you want to read more inputs about the same exactly topic, do a quick search and you'll find tons of info.
Now coming back to your question, here is my input, since I've already went thru this and read a lot about it and even tried different options.
- I've decided I wanted to stay with Pentax stuff, though Sigma and Tamron have some nice affordable options on the same range. I think you are missing on your list the fast Tarmon & Sigma f/2.8. (mmore options, if you like Sigma & Tamron)
- I always lusted for the DA* 16-50, and after renting it for a wedding, i concluded it was a very nice buy. BUT, since I have a K10D, I didnt want the headache trying to get a good matching copy. But the built quality is exceptional, weatherseals are peace of mind and the speed is there!
- I bought a 16-45 f/4. Decent price and very decent quality. Thing is, I DO NOT use 16<>50 that much other than a FA 35mm, so the cheaper DA 16-45 fits the bag because it is affordable, nice IQ and get used very slightly, to the point that I still havent really tested in harsh situations.
- Colors on the DA* and even the DA 16-45 are incredible. First day i received the rental DA* i could not believe the colors i was getting even shooting JPEG and the "crappy" PRIME on K10D.