Pentax smc DA* 50-135mm SDM Issue

On Tuesday I went to Everett Wa. to look at a possible project. The Nimitz, CVA 68 is back from a long deployment so I thought I would stop along the waterfront and take some photos. I pulled out my camera (k-3) with the DA* 50-135 on it and lo and behold, no auto focus. I bought this lens last year on black Friday, so its three weeks out of warranty. Anyway it was @ 29 deg F so I ended up using manual focus and with my bad eyes the result was not so good. Today I mounted the lens on my K-5 and nothing happened, then on the K-01 and it woke up. Tried it on all the other cameras and it worked fine. I wonder if it was just cold or if this is a sign of SDM failure.

Has anyone had this lens fixed at CRIS recently and would you have a cost?

Thanks,

Joe

I'd say that it's a sign of impending failure.  Did you buy the lens using a credit card?  If so, most times you will have an extra year warranty through the card company...something to check into.  It worked for me when I had an issue with my K-5 shortly outside of the Pentax warranty period.

Good luck.

Daryl

That sounds like it's going to fail. Fingers-crossed it was just moody that day.

I'm just wondering, when you mounted it on the K3 (and then the K5), were their batteries full? Was the K-01 battery full when it worked. Just trying to see if maybe it was caused by needing more jump-start power to get it going.

Let us know when it happens again (before you ship it back home to momma).

I fear my response will not help much but my 50-135 has been behaving something like that for at least a year and half. i bought it used from a guy who sold it very cheap because he was sure the SDM was dead. I left a week later for 10 days of backpacking in Utah with the 50-135 on the camera most of the time (1500 pictures) very few frustrations.  I have taken several thousand pictures with the lens since then. The problem is that it can be slow to start up and will occasionally balk at finishing focus but it will eventually do so. Sometimes it is beautiful with a BIF but really cannot be trusted for that. I am pretty sure that it is an SDM problem but I have waited to send it in because I like it so much when it works, which is most of the time. that I do not want to give it up for a month or so. I am sure I will do so eventually. Much sympathy with your problem. Nothing is perfect - or even close.

Do a Google search on: "How to deactivate SDM and allow for screw drive autofocus"

The first hit should be on the Pentax Forums page.

It tells how to use an older camera to read the lens firmware, make a change and write it back to the lens so that it always uses screw drive. I did it to my 50-135 and now I have a working lens again without having to send it in for a repair that may fail again down the road.

c57d wrote:

Do a Google search on: "How to deactivate SDM and allow for screw drive autofocus"

The first hit should be on the Pentax Forums page.

It tells how to use an older camera to read the lens firmware, make a change and write it back to the lens so that it always uses screw drive. I did it to my 50-135 and now I have a working lens again without having to send it in for a repair that may fail again down the road.

Have to strongly agree with Chris on this one. I deactivated 2 of my SDM lenses (DA* 16-50 and DA* 50-135). Pair it with K-3 and I never looked back on SDM anymore. I think screw drive focusing is faster with K-3 now compare to my old K-7 and K10D.

Cheers

Suwandi Chandra Photography

Its things like this that made me glad I bought a Sigma 50-150/2.8 instead.

Kent Gittings

Demoguy wrote:

On Tuesday I went to Everett Wa. to look at a possible project. The Nimitz, CVA 68 is back from a long deployment so I thought I would stop along the waterfront and take some photos. I pulled out my camera (k-3) with the DA* 50-135 on it and lo and behold, no auto focus. I bought this lens last year on black Friday, so its three weeks out of warranty. Anyway it was @ 29 deg F so I ended up using manual focus and with my bad eyes the result was not so good. Today I mounted the lens on my K-5 and nothing happened, then on the K-01 and it woke up. Tried it on all the other cameras and it worked fine. I wonder if it was just cold or if this is a sign of SDM failure.

Has anyone had this lens fixed at CRIS recently and would you have a cost?

Thanks,

Joe

Given it only happened the once it's all to easy to run round the room screaming SDm failure as seems to be the forum norm.!

The reality is in order of most likely ( 1 off occurrence).

1. AF/MF switch not seated in AF correctly

2. three way gear/clutch mechanism out of Sync

3. SDM tightening

4. seals slipped

5. Seals hardening/ diirt in barrell

6. gear damaged

options 1 and 2 are no cause for concern.

option 3 will be noticeable in that though AF will now function it will be slower than previous, You can easily asses this, In a free focusing 50-135 the lens will be fractional quicker short -> infinity than back again , the whole proses would take < 1.5 secs. If they are the same speed and greater than 1.5 sec then suspect you may have SDM motor beginning to bind.

for options 4-5 you can manual spin the focus barrel it should appear loose and tacky

If it feels tight, gritty or well damped you have a problem.

Though 3,4 and 5 are classed as SDM failure only 3 will be 'fixed' by modifying the microcode to allow screw drive.

It is relatively unusual for SDM to fail inside 2 years normally waiting till the 'nomal' warranty period outside the US has expired (24 months).

Check your consumer protection laws as in the UK we are covered for 6 years for 'faulty design' and I had my 4.5 year old 50-135 replaced by Pentax UK FoC (after some frank discussions).

KentG wrote:

Its things like this that made me glad I bought a Sigma 50-150/2.8 instead.

Kent Gittings

DAVID MANZE wrote:

KentG wrote:

Its things like this that made me glad I bought a Sigma 50-150/2.8 instead.

Kent Gittings

I must say I don;t understand your almost gloating admission you are deliberately rejecting some of Pentax's optically best glass based on 3rd hand reports.?

I have used multiple SDM lens constantly since 2008 , My failure rate is in line with what I'd expect form any similar technology lens from any other manufacturer (1 failure)

which gives a MTBF of 20 Years .

Yes USM/SDM/HSM/SWM will fail more often than screw drive but the silent drive, higher torque more than make up for the shorter life cycle.

Pentax's biggest issue with SDM was managing peoples expectations rather than any inherent failure in design, anecdotal evidence points to about a 4-8% higher failure rate fro the 16-50/50-135 in their early releases again pretty much in line with new technology releases.

Failure rates now seem to be in line with every other OEM .

Other forum member have had significantly worse experience than me and some significantly better, That is life , I wouldn't base my purchasing decisions based on either rather as I did research the technology and understand the real risks.

You get the same reports from dissatisfied users for any brand you just need to look

Her you go for Sigma

"I had a Sigma EX 70-200 f2.8 hsm II that had the AF motor repaired 3 times so I sold it before it was out of warranty and bought a Tamron instead."

(Google Sigma fail  this one is over at the other forum)

If you took heed of all of them you'd never buy a lens again

Lens Rentals is one of the best places to assess real reliability of lens (notice I said lens not brands)

Dave's clichés

kriztian wrote:

Hello Awaldram, the focusring on my 50-135 feels well damped. But it Always have and the focus is very accurat but a bit slow like all reviews are saying. It takes about 2 seconds for the focus to travel back and forth against a blank object. Are you saying my lens is about to fail? Cheers and happy hollidays

No but I would say your seals are putting additional load on the piezo motor so in the scheme of things is more likely to fail than one that doesn't.

if your saying 2sec back and forth that is quick , I'm talking 1.5 sec each way roughly.

Do you ever find it fails to do the double take and achieve lock.?

Having said that I don't think you have a case unless it does fail.

happy Holidays

p.s. if your not seeing issues I'd not worry

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kriztian

Britney Elvis wrote:

Please… where did you get the anecdotal evidence? Does that include failures after the '1 year warranty?

”Pentax's biggest issue with SDM was managing peoples expectations rather than any inherent failure in design, anecdotal evidence points to about a 4-8% higher failure rate fro the 16-50/50-135 in their early releases again pretty much in line with new technology releases.

Failure rates now seem to be in line with every other OEM .

Other forum member have had significantly worse experience than me and some significantly better, That is life , I wouldn't base my purchasing decisions based on either rather as I did research the technology and understand the real risks.

You get the same reports from dissatisfied users for any brand you just need to look

Her you go for Sigma

"I had a Sigma EX 70-200 f2.8 hsm II that had the AF motor repaired 3 times so I sold it before it was out of warranty and bought a Tamron instead."

First off anyone on this forum for a few years knows that the failures of the first two SDM zooms were much higher than any previous pentax lens (and any lens since)

Really 'Knows' and 'much higher' would you like to quote your source ?

… and that Pentax never officially acknowledged the problem…

Maybe the problem is not Pentax's ? surely if SDM was as prone to failure as you imply Pentax would have gone bust with warranty repairs.?

I suspect you have zero SDM lens along with Zero first hand experience and wonder at your vehement posts on the subject and what you angle is.?

I can only go by my knowledge and that is I have 4 SDM lens there all on average 5 years old 1 has failed that gives a mtbf of 20 years. That is something I know

It also seems 90% of anti SDM rants are made by people who do not own SDM ?

have a look @pf reliability survey (google 'SdM reliability survey)

the 3 lens with higher failure rates are 16-50, 50-135 and 17-70.

Yet the 17-70 has a good reputation versus the other two yet is statistically more likely to fail than the 50-135 !! This tells you a lot about 'perception' Vs fact and how your vision can be clouded by taking to much stock of 'web' reports.

and to give some perspective to those figure here is lens rentals failure rate worst offenders for other manufacturers.

These lens do not make 1 year between failures !!

http://www.lensrentals.com/blog/2013/08/lensrentals-repair-data-2012-2013

and to all the 'glad I went Sigma HSM' I give you a quote from Roger (a man who knows)

• Sigma’s big zooms still have trouble with their HSM motors and OS units, but Sigma really does seem to be doing better. Their large zoom lenses are still on the list but the frequency is lower than it used to be, in a year when my new accounting system made most numbers look worse. Sigma’s prime lenses and smaller zooms have excellent repair rates.

But the real issue has always been, since it was an obvious issue, why not extend the crappy 1 year warranty? Show your customer base that you respect them and will take care of a design flaw on your Flagship lenses.

You assume Pentax has a crappy 1 year warranty globally ?

the Uk has 2 years manufacturer warranty on everything and 6 year consumer warranty on faulty design.

In your Sigma example, it is an EX lens which I believe has a total of 4 years warranty and of course all Tamron’s have a 6 year warranty…

In the UK that is just acknowledging their legal requirements, Maybe the issue is Pentax are out to make money and will operate within the commercial requirements of the country their operating in.

I believe Pentax's US extended warranty comes in at a princely $19.99 given choice is good it is surely your risk if your decide to save 20 bucks . Bleating about opting out is just that bleating !!

If you don't like their options then spend your $ elsewhere and they may change it.

Is Pentax SDM more likely to fail than screw.? bet your life on it, Is it more likely to fail the similar technology from other manufactures the stats say NO.

When roger releases hie 2014 reports they will include Pentax so that will be interesting and maybe put the conjecture on SDM to bed, with direct comparison available with all other brands.

gus

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"It is not necessary to understand things in order to argue about them."
~~ Pierre Beaumarchais~~

As you asked where I got ny evidence that failure rates had normalized for SDM inc the 16-50 and 50-135.

Here are the stats form PF for 2011 (the only year with enough numbers)

percentage chance of failure worst to best

17-70 26%

16-50 23%

55 8%

300 8%

50-135 8 %

60-250 2%

200 0%

18-135 0%

I see no evidence to back up your claim on the frailties of the 16-50 and 50-135 as compared to the rest.

Could you post your evidence ?

You complain same old explanations but unless the facts change how can the conclusion?

I'm not a bif fan of Pentax's ultrasonic implementation and believe there was a lot cleaner ways to do it if you dropped backward compatibility, yet the accusations ledged against it I find unfounded and always without evidence.

For every member screaming from the rafters about their failed SDM there are 10 users quietly taking pictures with theirs.!

I have used Sigma lenses since my ZX-5n and Minolta Maxxum 9 film days and have yet to have any issues at all on any of them. I had one lens rechipped to cover newer bodies (300/2.8 APO). I even bought a couple of lenses people did not like (Sigma 90/2.8 Macro and Sigma 70-300/4-5.6) and both worked as advertised. Now I have never had a Pentax lens that had an issue either (except an FA 24-90/3.5-4.5 that was thrown in with a camera and I knew it had an issue). BUT I have never quite trusted Pentax's attempt at motor in the lens technology even though they invented it first. It took them too long to get around to SDM. Even Minolta had their SSM before them and this is the company that was last to get a DSLR out (although they invented shake reduction). Sigma has had HSM out of years, mainly because they had to compete with Canon's own lenses. So it is a much more proven system compared to Pentax SDM (or Minolta/Konica/Sony SSM for that matter).

But for me it only enters the equation after I compare the optics most of the time, assuming Pentax has a lens in that focal range. I still own plenty of Pentax lenses, some all the way back to the 60's. But these days, even for my Canon system, I am more inclined to include Sigma, Tamron, and Tokina in the potential buying equation.

Kent Gittings