Forgot Password
Pentax Camera Forums Home

Show Printable Version Search this Thread
09-26-2010, 07:02 AM   #1
Forum Member

Join Date: Feb 2010
Location: Boise, Id
Posts: 58
50-135mm SDM problem not a myth

I wanted the Pentax DA* 50-135mm for my wedding shoots, and I wanted it bad! What an amazing lens with a near perfect range to compliment my Tam 17-50mm and allow more reach than my Tam 28-75mm! Countless hours of looking for an alternative to this lens and I have seen nothing in this range that is as good optically at both focal extremes and as usable wide open. I read debate after debate. Is the SDM failure only a vocal minority complaining or an inevitability for all owners?

Yesterday, I visited my local dealer, for one more fondling of this lens, ala Mike Myers and "the" Fender Strat in Wayne's World, "It will be mine. Oh yes, it will be mine!" Mounted on a KX body I turned it on and gave my best, "I know what I'm doing, I'm a pro" focus test and......nothing. Hmm, must need to flip both the lens AF/MF switch to AF. Oh it is. Must be that the camera switch needs to ...oh, it is. Sensing the retail clerks impatience with me, as though she had something more important to attend to, I handed her the camera back. She gave it her best, "stand back, I'M a professional" and nothing....After switching the switches, cycling the power and pointing it around the room a bit, it suddenly began to autofocus, as though it had just awakened and noticed the user would like to begin shooting now. And this is a brand new lens, albeit a display.

To make a short story long, I was prepared to purchase one of these with the longest, best extended warranty available, suck up the extra money and enjoy the amazing optics. But, I saw the infamous "wake up" issue first hand on a new lens. As much as I want it, I don't think I can live with the prospect of a $1000+ investment not working as it should. I guess the search continues. Meanwhile, I'll continue to use my DA 55-300mm for the longer shots, which seems to do much better than you'd think, albeit with significant speed/focusing/aperture limitations.

Just my .02 on the SDM issue.

09-26-2010, 08:26 AM   #2
Veteran Member
KjetilH's Avatar

Join Date: Mar 2008
Location: Oslo
Photos: Gallery
Posts: 309
I haven't seen any reports on HSM failure in the Sigma 50-150. It's probably not as good, but I can't complain. Mine hasn't failed yet, and focus issues are probably sorted out if you try the lens in the store. You lose WR, but the price difference is, after all, significant.

Good luck on finding the right lens, even if you have to omit the 'pixie dust' (which could be what's getting in the motors and ruining them).
09-26-2010, 09:47 AM   #3
Senior Member

Join Date: Nov 2008
Location: BC
Posts: 219
I love my 50-135 dearly, but the SDM does have issues. It started to squeak during focusing, so I sent it to Pentax Canada (out of warranty I might add) They replaced the motor. (only charged me parts )
It is working wonderful now. But it is always in the back of my it going to fail again? If you do get it, you will love it. Just get extended warranty.
09-26-2010, 12:19 PM   #4
Forum Member

Join Date: Aug 2010
Location: Virginia
Posts: 62
Getting an extended warranty pretty much squashed my worries about anything happening to mine. I'm almost the kind of person who doesn't care that much how many times something has to get replaced or fixed as long as I don't have to pay for any aspect of it. So far, the warranty (as usual) has been a waste. I hope it stays that way.

09-26-2010, 03:48 PM   #5
Veteran Member

Join Date: Aug 2009
Photos: Gallery
Posts: 1,236
I noticed twice with my DA* 300 when I put it on, the screwdrive AF of the body and lens don't line up or something, preventing the lens from being able to AF with SDM. I just took the lens off and rotated the screw drive AF bit on the body and I was good to go after that. I don't know why that would make SDM not work, but it's interlinked with the screwdrive stuff I assume.
09-26-2010, 04:04 PM   #6
twitch's Avatar

Join Date: Nov 2009
Posts: 4,571
I bought a 50-135 with a 3 yr warranty. Having owned it now for only ~2 months, but used it a lot in the meantime, I can say I've never have a focus "wake up" problem. The SDM has been great; silent, accurate, and fast enough (but then I've been use to the 55-300 focus speed, lol). The IQ is amazing by the way, it seems every bit as good as my DA70 which is saying something.
09-27-2010, 09:00 PM   #7
Forum Member

Join Date: Feb 2010
Location: Boise, Id
Posts: 58
Original Poster
Thanks for all the input on this subject. I was convinced that I should run away, and yet, thanks to your the responses, I feel all the more drawn to the pixie dust. So who has the best warranty on this? (without the gotchas). B&H has run out of them.
10-13-2010, 04:17 AM   #8
Forum Member
Jan67's Avatar

Join Date: Oct 2010
Location: Prague
Photos: Gallery | Albums
Posts: 84
I consider to buy DA* 50-135 because of its excellent IQ but I am really afraid of SDM issue.
Do you think that SDM failures still remain or that production has in some way improved its quality ? There are not so many updates in related threads. Did Pentax reacted on petition regarding SDM ?
Do you expect any new version of DA* 50-135, with recently announced DC motor ?

10-13-2010, 04:53 AM   #9
Veteran Member
Reportage's Avatar

Join Date: Feb 2009
Photos: Gallery
Posts: 739
well, if Pentax is still using the same design as the 1st batch then be prepared. If Pentax has changed the design or components of the lens since then do take note of batch/serial number before buying a 2nd hand one.

as long covered by warranty or willing to pay for repairs then not really an issue. The big issue is if you get a really big job and the lens sdm decide to fail at that moment. Thats when knowing how to manual focus comes in handy.
10-13-2010, 06:06 AM   #10
Senior Member

Join Date: Aug 2007
Location: Perth, Australia
Posts: 268
My 50-135 is about 2 years now, and its still working.
10-13-2010, 06:28 AM   #11
Loyal Site Supporter
dcmsox2004's Avatar

Join Date: Apr 2008
Location: rhode island
Photos: Gallery | Albums
Posts: 7,331
fwiw.... i also considered grabbing this lens.... but i don't have the patience for an expensive purchase to 'crap out', just when i don't want it to......
it would be one thing if we were talking about a relatively inexpensive consumer lens, but many use this lens for capturing important moments, i.e., weddings, anniversaries (which may be paying jobs), and having to pack a backup (always a good idea anyway) , 'just in case'... is just not acceptable retail practice....
what exacerbates this issue is the fact that pentax's service, here in the states, is now outsourced. many forum members have complained about slow turn around time for repair and poor communication as well.......
this also ties in to the degradation in the retail support afforded pentax users....
pentax corporate should be called in on the proverbial carpet..... but then again, i don't believe they have genuine concern for their customer base.....
10-13-2010, 07:20 AM   #12
Wheatfield's Avatar

Join Date: Apr 2008
Location: The wheatfields of Canada
Posts: 10,157
On one of the other forums I inhabit, a poster who apparently was talking to a tech from Pentax Europe told us that an apparently dead SDM motor may not be dead.
Something in the lens discharges and kills the operation if the lens is left to sit too long.
Mount the lens, turn the camera on and leave it sit for a few minutes (obviously auto shut off must be disengaged) and the lens should start working.
Personally, I don't believe it, but I put it out there FWIW.
10-13-2010, 07:38 AM   #13
Inactive Account

Join Date: Aug 2008
Location: Michigan, USA
Photos: Gallery | Albums
Posts: 7,484
I've had mine since Nov '07 and have yet to have an issue with it. Sometimes it sits in the bag for months at a time. I'm not suggesting that people who have reported problems are being untruthful though. As to the what if it fails during a shoot crowd... Most people using cameras have two hands. With all the complaining about the focus speed (which I don't find any slower than my other lenses), the left hand sometimes works better anyway. Catch In Focus works beautifully with this lens. Dead SDM does not change the ability of the lens to gather and focus light. Finish the shoot, and send the lens in.

10-13-2010, 07:56 AM   #14
Inactive Account

Join Date: Apr 2010
Location: New Orleans
Photos: Gallery
Posts: 3,053
If the DC motor is actually new, do you all think that a DA* II 16-50 and DA* II 50-135 are around the corner?

  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
50-135mm, 50-135mm sdm, camera, debate, issue, k-mount, lens, pentax lens, range, sdm, slr lens, switch
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Similar Threads
Thread Thread Starter Forum Replies Last Post
SDM 50-135mm Lens darayusJEngineer Troubleshooting and Beginner Help 1 09-12-2010 10:31 AM
DA* 50-135mm SDM Squeak ViseMoD Pentax SLR Lens Discussion 13 08-05-2010 09:11 AM
DA*50-135mm f2.8 SDM Problems / No Problem rustynail925 Pentax SLR Lens Discussion 30 03-22-2010 06:08 PM
For Sale - Sold: Pentax 50-135mm SMCP-DA* 50-135mm f/2.8 ED IF SDM mmzymxf Sold Items 1 10-28-2008 01:01 PM
SMC DA* 50-135mm f:2.8 ED IF SDM Trub Pentax SLR Lens Discussion 5 08-23-2007 03:54 PM

All times are GMT -7. The time now is 01:57 AM. | See also:, part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]