[Verglace]

I found the 16-50 was the best Pentax lens I had, before that I had the 70mm Ltd and 15mm Ltd. It focused fast. The only problems were the weight, and also how silly it is that they made the zoom ring so tiny! Most people that borrowed the camera from me often tried to zoom in with the focus ring.

[Belcik]

Most people that borrowed the camera from me often tried to zoom in with the focus ring.

I have read somewhere that not using a quick-shift (people trying to use focus ring instead of zooming) can extend the life for SDM - anyone heard about this and can confirm it?

And BTW: is there any reason of having focus ring so big? After reading an article about those small plastic "things" on Pentax Strap, I would say that there is something behind the idea of wide Focus Ring....

[Ash]

There's no proof that avoiding quick shift has any benefit. I never used quick shift on my copy, and its SDM died a slow death in the hands of the next owner of the lens.

[kxr4trids]

My first 16-50 had SDM DOA, so that clearly wasn't a quickshift issue
My second 16-50 died a year and a half later, also without having the quickshift used.
The zoom ring is in a horrible location.
The proper way to hold a lens is from underneath, which is damn near impossible on the 16-50.

[Ray Pulley]

My wife gets mad.... Hates me with my camera, well - she hates how long it takes me to focus to be precise. So I decided to check the DA 16-50. Went to the shop, took it into me hands - nice big piece of lens.... And then I understood, how low usability they have...

Sure, the SDM works not bad, my copy seemed to have some back focus around 16... But the focusing zooming ring....

Who the hell made is so small and hard to operate!. I was barely able to make some test photos, I was trying to figure out - why someone wanted it to be so hardly accessible and unusable. Is it only me that thinks this way, or maybe it is only the question of getting used to it?

I like WR, I like not bothering about the weather - but it seems that I do not have a real alternative in the kit like range - am I correct?

[EDIT]
Sorry - conffused ZOOMING and FOCUSING ring. Zooming is so small.... and Focusing is so big...

I have had my 16-50 since the second batch hit the US. My first one suffered from SDM failure, and it was replaced, not repaired. The replacement lens has been perfectly reliable since then.

This lens is almost always attached to one of my bodies, starting with the K10 and on through the K5. It gets a lot of work, and overall, does a reasonable job.

My summary:

WR - Great. I have shot with it in the rain and watched my Canon 5D co-shooter put her camera away and worry about me ruining my camera and lens while I kept on shooting with no issue.

IQ - so-so. The lens is not great wide open at the 16mm end, with soft edges and a fair amount of distortion to boot. I do not shoot at the extremes with this lens, and stopped down or zoomed a bit, it performs fine. Not great, but fine. IMO one of the main reasons for a fast 2.8 zoom is not how good they are at 2.8, but how they are much better than a cheaper lens one stop down where the cheaper lens is wide open.

AF - It is quiet, but pretty slow. Every screw drive lens I own will zip to focus lock much quicker than this lens. My 50-135 is just as slow.

I have no problems with the controls, and like the quick-shift focus.

All that said, I recently bought the Sigma 17-50 f2.8 HSM, and in almost all respects, it is a better lens than the 16-50. It is sharper, shows less distortion (yes it is 1mm less wide), is just as quiet, and seems faster to focus, although I have not yet tested the two head to head in an objective AF speed test.

The Sigma is not WR, and has no quick shift, both of which are drawbacks, as is the moving focus ring and zoom ring that rotates backwards of every other zoom I own.

For me, however, the dog slow SDM focus was just wearing me down, so I went looking for alternatives and am willing to live with the drawbacks for faster AF, especially if the IQ is the same or better.

Of course, with the latest pricing from Ricoh, the Sigma was much cheaper as well, but that might not be the case where you live.

I hope to find the time to test them both head to head for IQ and AF performance in the near future, but so far, the Sigma looks to be a better value that you should definitely consider with the 16-50.

Ray

[Belcik]

Thanks Ray Pulley, I will try to test both of them.

[liukaitc]

actually 16-50 focus pretty fast. it is on par with sigma 17-50. it focus more accurate than sigma 17-50 (might be that sigma lens always need adjustment or calibrate)
but yes sigma 17-50 is a lot better wide open than pentax 16-50. you do not fear of using f2.8 on sigma 17-50. but I always tend to avoid f2.8 on 16-50. I usually start with max f3.5 on it.

[Ray Pulley]

actually 16-50 focus pretty fast. it is on par with sigma 17-50. it focus more accurate than sigma 17-50 (might be that sigma lens always need adjustment or calibrate)
but yes sigma 17-50 is a lot better wide open than pentax 16-50. you do not fear of using f2.8 on sigma 17-50. but I always tend to avoid f2.8 on 16-50. I usually start with max f3.5 on it.

My impression about the speed of 16-50 versus the 17-50 Sigma is that they are about the same, and I would not call them fast. However, I have a definitive way of testing speed to lock and I will do so when I have a little time.

So far, the 17-50 has not been a problem with focus accuracy for me.

The 50-150 Sigma seems noticeably faster than my DA* 50-135, but once again, I will test when I get a chance.

I certainly agree about the 16-50 being optically weak wide open, and sometimes think that Pentax should have stopped at 17mm.

I really wanted the 17-70 f4 to be a good all-around lens as I often want a little more reach than 50mm, but unfortunately, I have seen far too many reports of soft images from that lens, including two that a fellow shooter tried and returned.

Ray