[Anvh]

The DA* 16-50 is more versatile being a weaher-sealed zoom, but I would agree with Adam that there may be better alternatives for the price. I've been fairly happy with it (zero issues with SDM), but overall I like the DA* 50-135 much better.

But the DA*16-50 goes together very nice with the DA*50-135.
If i would go with sigma i would take the 17-50 and the 50-150 off sigma, that's of course also an option.

[polachekphotography]

To clarfy, I'm not displeased with the performance of the DA* 16-50 and the build quality (at least of my copy) is excellent. I've found it to be a very good lens, but I've just been more impressed with the IQ of the 15 Ltd and the DA* 50-135. At the time that I purchased the 16-50 (a HUGE step up from the kit lenses, lol) I didn't even look at any alternatives as I wanted genuine Pentax. However, if I were buying today I might take a closer look at the Sigma or Tamron.

So if it were me I would consider keeping the 15, adding the 50-135, and then saving up for the 16-50 or something equivalent.

[frank]

My 1650 doesn't have SDM problem, but after I found out how fast the AF became after converting it to screw-driven AF lens (helped a friend do the conversion on his copy which had been dead for over a year), I converted mine to a screw-driven lens too. Can't be happier w this lens

[Anvh]

polachekphotography i wasn't attacking you, was just saying that the two match eachother really well, they are like brother and sisters, i at least won't consider adopting another brother for it.

[polachekphotography]

No worries, I didn't feel you were attacking. No offense taken.

[rvannatta]

I own all three of the pentax zooms you have in mind-- the 16-50, the 50-135 and the 60-250. I bought the 16-50 shortly after it was introduced and have probably taken more photos with it than with all the rest of my lens family combined. though I own a variety of short primes the 16-50 has been my default walking around lens
for about 6 years now.---bad mouthed often but loved by me. As for the 2 longer zooms I had a very unhappy experience with the 50-135 almost the first day
I took it anywhere. I obviously own way too many lenses to take them all with me, so my custom is to carry a couple lenses with me when I'm not expecting
to take any pictures, but...... so shortly after I bought both the 50-135 and the 60-250, I tossed my camera in the bag, and grabbed the 50-135, and headed
down the road not expecting to see anything photo worthy.

Naturally I drove right up on a heard of elk that ran up the hill in an open spot a couple hundred feet away and stopped with a nice background to stare at me.


All in all the photo came out fairly well, but I had to crop it a lot more than I would like and if I had had sense enough to put the 60-250 in the bag instead of
the 50-135, that bunch would have filled the frame full. I still remember the picture I didn't get, and so help me I haven't put the 50-135 on the camera
since then, and that was in the fall of 2011. Don't get me wrong, the 50-135 is a really nice lense, Just don't pack it around when you should be carrying a real
telephoto. My suggestion is skip the 50-135 unless you are doing indoor photography--- a basket ball game, etc., and if you think you can't live without
an intermediate length lens get a 100mm Macro. they work just fine for general photography and you can take closeups as well.