Getting upset with Pentax

linkyou did not mention the lens had an sdm failure, had been repaired and you were still having concerns with it... in your description when you put it up for sale... or am I just confused?
Sometimes I read things between the lines that others do not. sometimes I'm wrong.
If I was unduly harsh in my frist response, I was also quick to apologise.

Would love to not argue further, but you have continued the personal insults against me.

First off, while you did agree that you were abrupt and flippant – this was only after you basically said I can’t take photo’s worth a crap. I’m sorry, but I find it hurtful and wrong that the first thing you come up to say to me is that. I’ve been a very proud supporter of Pentax over the years and have spent thousands of pounds on gear and I'm quite upset about this still. Being overly flippant would be something like saying your a moron for thinking about switching platforms, and that I’d live to regret it or something ... not the comments said above. There really is no excuse for that type of attack on anyone who has been a long standing member of this forum. So do please excuse me about getting so angry at your comments and not taking the time to scroll down a page to carefully read your next set of comments. If I was in your situation I would probably be pretty embarrassed with myself, but we're two different people. My guess is that you feel you have a right to personally insult anyone who is unhappy with Pentax.

Next, I really do wish I could find the article that I read prior to buying my lens - I'm now certain it was on the dpreview forums and it had a picture if the lens elements and which one wasn't in the right place. I can't remember if it was lens separation or the distance between lens elements or what it was - but there was some sort of problem. Either way it made me quite picky about which lens I got. I'm quite happy with the IQ of my lens though and don't have any problems with it except for the SDM failure. As I have no idea what it was that I read about the problems I'll fully apologise for the level of personal harm this seems to have done to you as well as to anyone else who feels as hurt as you do. I apologise profusely - I'm very sorry.

Finally, as you are now questioning my integrity, I informed the member(s) who contacted me on the forum with regard to purchasing the lens that the SDM was repaired and had a full year Pentax certified warranty. It was repaired by the Pentax UK people (i.e. the 3rd party company which does all their stuff in the UK, but they are the official real deal, I think it's Johnsons or something like that). That’s about as good as it gets, but not good enough for me as I kept thinking it would fail (and apparently it was not good enough to each of the people who contacted me on the Forum as they didn’t want to buy the lens either after being informed). That’s why I sold it on eBay eventually.

I'm going to stop responding to you now Don.

It should be possible to have contrary views and not come to blows over it, so please call it a day now and move on, both of you. I don't want to have to lock the thread, so let's get back to the original discussion, as a discussion not a shouting match.

I'll agree with Whelmed here. It was Don who took it up (several) notches and for no reason at all started publicly questioning Whelmed's ability to take a photograph (which is undoubted, as anyone who has been a member of this forum for the last year or so would know), as well as deciding he was a troll (also clearly untrue, for the same reason). Coming out with a brief apology doesn't cut it. Nor does trying to minimise the insult by describing it as 'abrupt and flippant' - when it was quite clearly much more offensive than that.

The matter is closed Tim, so we'll reluctantly have to lock the thread if we can't move on.

After 3 pages of comment (kind of), I still have not the first idea what on earth this is supposed to mean.

I too use the da 16 -50 lens. My experience is that it is a good lens except for the SDM. I have had to have mine serviced twice now as the autofocus will become erratic or stop working altogether. The problem each time was the SDM which was replaced.

Photozone maybe?
I believe they mention they had replace the first model because of the lens aliment, the elements didn't line up like they should. You hear it in other lenses as well but considering the DA* is a pro lens you should think they had better quality control on them

I've the two SDM problematic lenses, hopefully i never get a problem if i do i might ask them to make it an SDM only lens if they can, throwing out some linkages might help hopefully...

Rarely, though, do other brands allow their flagship professional-grade zooms to become a running joke to such an extent that people buy Sigma zooms for reliability (great as 'modern Sigma' QC is, try finding a Canon user who favours their reliability over that of the L series). If the DA Limiteds represent the best of Pentax's modern lens design (not a verdict I'd take issue with), then the ongoing PR fiasco that is SDM must surely represent the worst

EDIT: On the topic of the 16-50 specifically, aside from SDM issues they are reported to have a higher-than-usual incidence of 'decentering issues' (ie being built squint). In fact this has been suggested as a possible reason why the 16-50 and 50-135 seem more vulnerable to SDM failure than other lenses with more glass to move (e.g. the 60-250) which use the same motors.

Maybe... so if your lens fails it doesn't matter since it was already bad to begin with, if so you should always demand a new one...

But yeah it's only the DA*16-50 and DA*50-135, the DA17-70, DA*60-250, DA*55, DA*200 and DA*300 doesn't seem to have much problems with SDM, at least never heard of one except dirty contacts.

I wonder if they might replace the first two with an updated SDM only model in the future?
Hopefully the simpler design might help and maybe they can also fit them with round aperture's while they are add it.

I could have sworn all the DA* lenses had rounded aperture blades.

Edit: Nope, just 9 blades.

The 17-70mm is starting to build itself a bit of a reputation as a SDM problem lens. I recently bought one off Ebay and couldn't get the thing to AF on anything using the 50-70mm range .. it just wouldn't lock.

Did a bit of searching and it seems to be a known problem with some of the lenses.

That's bad news Mike
But the AF did move right but just didn't lock, at least that's better than have the SDM not working at all...

Better in that it will AF from 17-50mm I suppose but still useless from there on in.

Maybe there is hope they can fix it with a firmware upgrade although they would have probably done that by now...