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01-09-2010, 09:51 AM   #1
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SDM issues DA*16-50mm

SDM issues again.

It's a great lens when it works. Mine was good for the first half of my ownership. But this is my second version. I was one who bought early and the lens BF's terribly (6-7 CMs at 30Cms distance). I returned that lens to the store ASAP. Waited a few months and bought my current version. The BF/FF problem seems to be resolved on new lenses over the past year or more. Plus we don't hear these issues with SDM primes Although there are few out there yet).

I can MF focus the lens much faster than the camera can or the SDM can. I have 2 K20D bodies. One the SDM is disabled and the lens works in ScrewDrive only. I accidentally shorted something while switching lenses in the dark and now it's an SD lens (actually it's in the body, not the lens). The other is SDM as normal.

In bright sunlight with high contrast, the lens works just fine. If there's any challenge in the scene (low contrast, lower light etc.) it plainly sucks. Constant little adjustments till it locks focus. It's brutally slow.

There's really no substitute. I've owned the Sigma 18-50mm EX (both the non and macro versions) and they are not as sharp. The Tamron 17-50mm is having issues as well. Neither is as wide. Neither is WS. So there's no real replacement.

Last edited by Peter Zack; 02-25-2010 at 07:33 AM.
01-09-2010, 10:12 AM   #2
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dang, Peter Zack! That really sucks. I know you use that lens a lot and I'm really sad to hear that it's become the paperweight that it is. Would you consider using it in manual focus mode only?

Still, this is not good. And I too find SDM a bit on the slow side (compared to screw drive, and especially to other brands). I find SDM just doesn't save you if a critical moment hits. It takes a couple of 'ziff ziff' moments before it finds the lock focus point. Something that i personally have to compensate for with my technique.

I've since moved to primes to cover the DA*16-50. I am considering doing so for the DA*50-135 as well.
01-09-2010, 10:38 AM   #3
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Resist the dark side... don't try the D700+24-70/2.8 combo...

Sorry Peter... couldn't resist... :-)

When i've switched, I was looking into Tokina version of the 16-50... but ruled it out as it was far inferiour in sharpness even compared to Tamron... Though, for some reason Tokina sells it's version of this lens with no internal motor.... so was the 50-135.... I wonder why...

Last edited by alexeyga; 01-09-2010 at 11:07 AM.
01-09-2010, 11:20 AM   #4
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Since I am planning to use my Pentax for similar situations... makes me wonder about sticking around as well. In weddings, sometimes you have a split second to take that picture. With my DA*55, as great as a lens it is, I am most likely going to miss that shot... and I have.

I agree about the kids scenario. I was using my film camera when doing photos of a baby and you have to be FAST. With manual focus and full frame viewfinder, I can be fast. I can imagine with the slower DA* SDM in that scenario, the trouble are much more exaggerated. I'm guessing a couple of closed eye lids and stuff like only 3/4 people looking into the camera?

Would you consider going screw-drive lenses only? I'm thinking of replacing the DA*50-135 with a Tamron 90mm lens. Maybe DA 35mm Limited Macro to replace your DA*16-50?

Last edited by Peter Zack; 02-25-2010 at 07:26 AM.
01-09-2010, 11:30 AM   #5
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See if you can hold of until Sigma releases the SD15 Peter (although Sigma does have it's issues it's sweet in the studio, and for weddings)

Although I'm not shooting Pentax digital I'm really sorry to see the issues they're still having with that lens. Like everyone else, I'm impressed with the IQ, when someone has a good copy, however when they need to try 3 or 4 copys before getting a good one there's something wrong.
01-09-2010, 11:39 AM   #6
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Actually I'm quite certain that Nikon is overpriced... 24-70 being one of the finest lenses in Nikon arsenal goes for ~1500$US used... that's crazy!!! But for a full time pro like you, D700+24-70+70-200VRII should pay it-self out fairly fast... B.t.w. rumors are, D700s is around the corner... just wait for it to be released and regular D700 prices will fall through the floor, just like D300 did...

Last edited by Peter Zack; 02-25-2010 at 07:27 AM.
01-09-2010, 11:50 AM   #7
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I share your frustrations. In good light, the lens is amazing, and most of my best shots are with this lens. In low light, however, it's a nightmare, slow and hesitating. All the SDM issues are troubling as well. I'm continuously considering switching, most likely to Nikon, but what stops me is this:

Pentax K7: $1030
Pentax 16-50mm: $745

Nikon D300s: $1500
Nikon 17-55mm: $1440

So the Nikon system is over 60% more expensive. For other accessories, I can go third-party, but no third-party manufacturer makes a weather-sealed normal lens. I want an APS-C system, by the way, which I feel is the best compromise between performance and size.
01-09-2010, 12:11 PM   #8
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Regarding focusing speeds, I find the K-7 to be a lot faster than my old K20D.

01-09-2010, 12:19 PM   #9
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Sorry Peter,

Welcome to my world. Now that such a well respected moderator and photographer has said it, I know I won't be mercilessly flamed.

I have been loyal to Pentax for decades. I still have my first Pentax camera, the MX. The QC problems I had with the 16-50 requiring me to go through 3 copies before I just got a complete refund, started to sour me. Then, about a day before my 50-135 was to go out of warranty, the SDM failed. Then I got a replacement from Pentax, and soon after, that one started showing the telltale signs of "SDM". So I got that one replaced, and then promptly sold it. The QC problems, along with the glacially slow AF told me enough was enough.

Those experiences made me do something I hadn't before: try the competition. I spent some time with a 7D and a lens that was ring-USM. I was dumbfounded. It was like using AF for the first time. It made me a bit angry that I was ignorant of how far behind my brand was. The Pentax forums rumors about how the competition sacrifices accuracy for AF speed were just wishful thinking from people that didn't want to face the truth. I tested in every condition I could think of; dark rooms, light, outdoors, sodium lights with motion towards the camera. etc. etc the number of shots I took that were out of focus were very minimal.

Again, I completely understand your frustration, and I share it.
01-09-2010, 12:21 PM   #10
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This is not good at all!

I probably entered the Pentax world at the worst time and...
Went from fast AF to slow, quality ring motors to SDM, safe future to uncertain....

Why? Call me a complete idiot but i cant answer that.
What i can say is that im absolutely in love with Pentax!
Will never change brands again.

BUT: What we need is that more people like Peter, ie people who shots for living, use their voices to make a difference!

And that the rest of us "happy enthusiast" will support them, and stand behind them! Even if you only shoot old MF lenses.....

We should all help to make Pentax better!

I am about to wage my own litle war against them with my 50-135 trouble, and will not give up!
01-09-2010, 12:39 PM   #11
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Are you serious? I hope they are just saying that publicly so they don't start a returns firestorm. Hopefully privately they are making changes.

In the meantime, I am faced with making the sad decision to downsize my Pentax gear while I can still get a return on them. I will probably scale back to just the k10d and the lenses we use for the satellite flights which are manually fixed (and taped) focus. :ugh:

I take solace only in the fact that at least i don't have to earn a living from my photography (which would be a joke ) That is why I feel doubly bad for anyone that does.

Last edited by Peter Zack; 02-25-2010 at 07:28 AM.
01-09-2010, 01:47 PM   #12
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As I only picked up the 16-50 last week I obviously have no long-term stress testing myself... (I do have a 50-135 for 6 months which is great). Is unfortunate that you have these issues

In relation to the 16-50 / SDM polls... a fact of life is that the voice of unhappiness is always stronger... but there seems to be more defective units than should be expected for the amount of money changing chands here.

I dont believe Pentax would ever openly admit design issues (and the associated $ impact)... but rather I expect internally they are making/have made adjustments to quietly close quality gaps... I also believe to have read that the defect rate seems less today than at points in the past.

On the 16-50 I have... only have done limited testing but focus looks spot on, I actually find SDM to be reasonably quick (a good deal quicker than the kit lens, and also quicker than the 50-135 which I suspect is due to less focus throw), also did not seem too sluggish in poorer lighting... again, this cannot compare with the extent of the experience of others but my impression till now is great.
01-09-2010, 01:58 PM   #13
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I take solace only in the fact that at least i don't have to earn a living from my photography (which would be a joke ) That is why I feel doubly bad for anyone that does.
I *do* plan on doing business with my Pentax... hmm... if my lens fails during a key wedding shoot, I can consider myself done. And that scares me. Arguably though, I'm sure other manufacturers have issues with their lenses too. I heard some Canon lenses had some issues?

Peter Zack, curious as to how long you had the lens? We have a 2 year warranty in Canada don't we?
01-09-2010, 02:32 PM   #14

Sorry to hear of your issues Peter... I have longed for the 50-135, but not until the sdm issues is 'admitted' and solved or a given a 6 year warranty like the tamrons have. How sad that the Pro zooms of the Pentax system are seemingly so crippled. And that time seems to take such a toll on the drive system.

Our own Gruoso has the D700 with I believe the 24-70 (I could be wrong on the lens). I got to shoot a few shots with it... It is quite a camera.
01-09-2010, 02:44 PM   #15
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Wow Peter, just caught onto this thread and feel for you.
It's not just addressing your own personal needs - as you do it for a living, the gear should live up to expectation - and set a standard for the company to convey to the rest of the customer base.
Your expressed concerns are shared by many others, myself included.

I've contemplated many times selling my copy but given its beautiful rendition I've balked each time. It works really well with my 540 flash, like no other lens. I wonder what I could possibly replace it with and can only come up with the Tamron 17-50.

Decisions, decisions.
If you sell yours Peter, I'll sell mine.

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