[rvannatta]

I've been fortunate with my DA* 16~50/2.8. I've had it three years now and no problems as yet. Isn't it sad I had to add "as yet" to the end of the sentence? Every time I use it I have to admit I'm wondering if this will be the day. I always have a backup lens or two in the bag just in case. Optically, as Pat notes above, for a zoom it is very good and I especially like the colours. Hope my luck continues.

Tom G

They can't be all bad. I have one of very oldest ones in the forum serial number database. I've used it as my walking around lens of choice
since I got it, and it's still happy and so am I.

[Ponosby Britt]

They can't be all bad. I have one of very oldest ones in the forum serial number database. I've used it as my walking around lens of choice
since I got it, and it's still happy and so am I.

I'm also feeling guilty here. My 3 year old, well traveled, well used 50-135 and used 17-70 from KEH have no issues. Worse, two K-5s, 1 new and 1 returned to Amazon with 120K+ exposures and they still work! I feel guilty every time I deposit my customers checks. If they only knew what they could have from a photographer with superior equipment. Now you understand why I use a nom de screen. Oh the guilt, the shame!

[lightbulb]

Let me help you by sending your gears to me ha.

[ve2vfd]

Well, the good news is that Pentax Canada replaced the SDM motor and fixed the clutch mechanism in my 16-50 and sent it back to me in record time! I had my lens back within a week day for day.

The bad news is that they did not fix my 60-250 properly and I'll have to send it back, I was able to reproduce the problem both on and off camera within minutes of unpacking it.

Pat

[crazy_oam]

Hey , I saw a ebay post about cheap 50-150 with SDM failure and claim that this system
can DIY repair, is it true ?. can any one advise me to find DIY instruction for repair the SDM ?

Thanks,

Ohm.

[Adam]

Hey , I saw a ebay post about cheap 50-150 with SDM failure and claim that this system
can DIY repair, is it true ?. can any one advise me to find DIY instruction for repair the SDM ?

Thanks,

Ohm.

In most cases it's not an easy repair because the motor needs to be replaced, so I would just buy one with working SDM to begin with.

[ohce]

I have seen one Chinese guy fixed the SDM issue. Here is the link with many pictures.
http://www.soomal.com/doc/10100003594.html

Hey , I saw a ebay post about cheap 50-150 with SDM failure and claim that this system
can DIY repair, is it true ?. can any one advise me to find DIY instruction for repair the SDM ?

Thanks,

Ohm.

[EarlVonTapia]

I have seen one Chinese guy fixed the SDM issue. Here is the link with many pictures.
http://www.soomal.com/doc/10100003594.html

Nice link. Putting tape on the contacts is quite clever.

I took apart one of my junk zooms just for fun, and the second I popped off the mount, all of the little contacts sprang up and went on my carpet in every direction. It took about an hour to find them all. Tape would have prevented that.

[ve2vfd]

I have seen one Chinese guy fixed the SDM issue. Here is the link with many pictures. http://www.soomal.com/doc/10100003594.html

It's the same "repair" that is in the Lenses section here on the board. https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/130429-diy-sdm...us-repair.html I do like the way it's well illustrated.

Please be aware that is it not a permanent fix. It will loosen up a seizing motor and you'll get a bit more life out of it, but if the motor has seized to the point of burning out this will do nothing. I would certainly NOT start buying dead SDM lenses thinking this will be a miracle fix.

Pat

[Medium FormatPro]

Lets compare any and all versions of sdm; which would also include what Sigma calls their version the hsm.

Which would the general audience rather purchase??

The Pentax 16-50… The older version have massive issues to state it mildly. I've seen a boatload of them fail well within one year of purchase; even more fail just outside of warranty. And then what - send it back for how many weeks and be without the lens for that long? Even the newer version is not much better.

Compare that to items like the Sigma 14-60 (not sure if I have the focal length correct, but it is about that range). The Sigma has a much better price, better optics, faster & more accurate focusing. The Sigma also has none of the hsm issues that Pentax has with sdm.


Pentax is actually losing customers over issues such as this - lack of quality control in numerous Pentax items. Pentax also not stepping up to the plate and being responsible.

Verdict; Sigma wins yet another one over Pentax

[clover]

It's the same "repair" that is in the Lenses section here on the board. https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/130429-diy-sdm...us-repair.html I do like the way it's well illustrated.

Please be aware that is it not a permanent fix. It will loosen up a seizing motor and you'll get a bit more life out of it, but if the motor has seized to the point of burning out this will do nothing. I would certainly NOT start buying dead SDM lenses thinking this will be a miracle fix.

Pat

There is a way to permanently fix it, by no more using the SDM
https://www.pentaxforums.com/forums/maintenance-repair-articles/208353-how-de...m-f-2-8-a.html

[Alizarine]

There is a way to permanently fix it, by no more using the SDM

I guess this firmware hack will become so popular Pentax will take notice of it, and probably do one of two things:

a. Admit that there's an issue with the SDM design and release an updated version of it;
b. Release a firmware version that locks third-party hack software from ever touching it

[clover]

By the way, the 16-50mm is probably ending its career because of the comnig 24MP sensor, so it will be necessary to improve it...

[frank]

Lets compare any and all versions of sdm; which would also include what Sigma calls their version the hsm.

Which would the general audience rather purchase??

The Pentax 16-50… The older version have massive issues to state it mildly. I've seen a boatload of them fail well within one year of purchase; even more fail just outside of warranty. And then what - send it back for how many weeks and be without the lens for that long? Even the newer version is not much better.

Compare that to items like the Sigma 14-60 (not sure if I have the focal length correct, but it is about that range). The Sigma has a much better price, better optics, faster & more accurate focusing. The Sigma also has none of the hsm issues that Pentax has with sdm.


Pentax is actually losing customers over issues such as this - lack of quality control in numerous Pentax items. Pentax also not stepping up to the plate and being responsible.

Verdict; Sigma wins yet another one over Pentax

Sigma HSM failure rate is pretty high too:
sigma hsm failure - Google Search

[clover]

Even Nikon and Canon consider that "SDM" like motors are pieces to change as far as they get old...