Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
06-11-2009, 04:16 AM   #61
Senior Member
jfsavage's Avatar

Join Date: Jun 2008
Location: Charlotte, NC
Posts: 211
QuoteOriginally posted by PentaxPoke Quote
After not using the lens for a while, I take it out of it's bag, and connect it to the camera, and it won't auto focus. I turn the focus ring back and forth a bit, and then try auto focus, and it does so grudgingly, and intermittently. I have to operate the auto focus repeatedly until finally it starts working reliably. It behaves as if the SDM motors are "frozen" and have to be worked in a bit before they start responding.

This happens every time I put on the lens and it has been sitting for more than a few days. To head off the inevitable questions, here are some conditions:

-The lens is always stored in its bag, indoors, in an air-conditioned room.
-It has never been damaged or even bumped.
-The contacts are very clean.
-It does this on the k20d
-No other lens I own has AF problems. Only the SDM on the DA* 50-135.
-I have the latest k20d v1.03 firmware
-The lens is attached properly

I guess I am just not meant to have an operable DA* lens. First 3 defective DA* 16-50's and now this!
I got a 50-135 from Amazon Wherehouse deals and it had the same issues. I sent it back, which was a shame as it was a great deal.

06-11-2009, 12:02 PM   #62
Junior Member
Zadilla's Avatar

Join Date: Mar 2009
Location: Miami
Posts: 32
jfsavage: I'm interested to hear how long ago did you get it from Amazon? Was it directly from Amazon or one of their resellers? Less than a month ago I purchased one from Amazon as well and so far so no problems. I called Amazon about some scuffs on the box. They assured me that they were probably shipping related and that this was a new lens. They also offered me an additional $150 to keep the lens. Which I did after contacting Pentax to confirm the warranty.

Is there anyway to find out the manufacture date of the lens?

Thanks.

Angel.
06-11-2009, 03:27 PM   #63
Veteran Member
wlachan's Avatar

Join Date: Sep 2006
Location: Canada
Photos: Albums
Posts: 2,626
QuoteOriginally posted by Zadilla Quote
They also offered me an additional $150 to keep the lens.
Wow sounds like they are trying hard to get rip of this lens.
06-12-2009, 12:50 AM   #64
Veteran Member




Join Date: Jan 2009
Location: Canada
Posts: 1,255
QuoteOriginally posted by wlachan Quote
Wow sounds like they are trying hard to get rip of this lens.
The lens is cursed.
But it comes with a free frogurt.
The frogurt is also cursed.

07-17-2009, 01:39 PM   #65
Veteran Member
bwield's Avatar

Join Date: Mar 2008
Posts: 444
Maybe just a little Paranoid..
But instead of starting a new thread I though I would just add to this one.

My newish (June 10. 09) Pentax 50-135mm is PERHAPS starting to show some signs of SDM failure.
What I have noticed is that if I am out shooting 95% of the time there is no problem, however I have run into a problem when focusing on something close to the minimum focusing distance.
If the lens locks focus on "Object A", but I wanted it on "Object B" when I go to refocus it USUALLY works, however I have found that if Object B is marginally (but enough so tthat its out of focus) away from object A that the lens locked on to, the autofocus will refuse to change focus.
In these cases I will quickly point the lens to a far away object and the motor will kick in again, focus, and I will try again.
It has happened enough that I have wondered if there is a problem with the focusing, and a pentax Canada rep said it sounded like "Focus Lock"
Has anyone else had a similar experience with their SDM lenses?
07-17-2009, 03:02 PM   #66
Veteran Member
wlachan's Avatar

Join Date: Sep 2006
Location: Canada
Photos: Albums
Posts: 2,626
QuoteOriginally posted by bwield Quote
Has anyone else had a similar experience with their SDM lenses?
Without actually trying your lens, I can only guess, but yes, I think this is a camera issue, not the lens. I have similar experience with my FA lenses, but usually with distant target which is small. The AF sensor covers a wide area and sometimes sees more than we think. Also, to the camera, in-focus is not a point but a range. Anything within that distance range could be determined as in focus by the camera. This is also the reason AF assist is not as precise as manual focus.
08-27-2009, 09:47 AM   #67
Forum Member




Join Date: Feb 2009
Location: Canada
Posts: 58
Option to disable SDM

The autofocus of my DA*16-50 started failing on me last spring after having the lens for 6 months. Pentax Canada replaced the lens under warranty.

The autofocus of my DA*50-135 failed last month after having the lens for about 21 months. Luckily the warranty for this lens is 2 years in Canada. Pentax Canada again replaced the lens under warranty.

I was in Henry's the other day to test out the K-7. I asked for them to mount the DA*16-50 for me to test it with. The autofocus on this lens did not work either.

Not a good track record.

My only saving grace is that I could still use the DA* with a failed SDM by downgrading my K10D firmware to a hacked version of 1.20. I did this after my 50-135 failed and was able to use the lens until I sent it back for service.

At this point, I'm really worried about upgrading to the K-7 unless Pentax adds an option to disable the SDM. There is an honest (ie. no loss of face) reason to do this: The screw drive in the K-7 is faster than the SDM (from what I understand). If Pentax doesn't provide an option like this, I will seriously consider selling all of my Pentax equipment and switching to Canon when it comes time to upgrade. It is either that or face the expensive (and inevitable?) repair costs in the future to keep my SDM's functional.

- Phil

Last edited by boardhead; 08-27-2009 at 10:12 AM.
08-27-2009, 11:29 AM   #68
Site Supporter




Join Date: Jan 2008
Location: NC
Posts: 787
so far the problems seem to circle around the 1st 2 DA*. the 16-50 and 50-135.
i wonder if this SDM issue has reared its ugly head in the 17-70, 60-250 (too new to tell),
DA*200 DA*300, DA*55.

pentax NEEDS to address this.

08-28-2009, 04:58 AM   #69
Forum Member




Join Date: Feb 2009
Location: Canada
Posts: 58
Well, yesterday when I got home I discovered that the AF was broken on the replacement DA* 50-135 that I had picked up earlier in the day. No only that, but the manual focus ring didn't work either.
08-28-2009, 07:36 AM   #70
Inactive Account




Join Date: Mar 2009
Location: NC
Posts: 12
I have a DA*300 that I bought used from another member and since buying it I have used it ALOT with no problems whatsoever. So far so good. I really want a 50-135 but because of all of these issues I may hold off and think about it for awhile.
02-02-2010, 01:41 AM   #71
New Member




Join Date: Aug 2009
Location: United States
Posts: 19
I've just started experiencing this problem in my DA* 50-135. I last used the lens maybe 2 months ago...and when I took it out over the weekend, no autofocus. I think I eliminated all other possibilities, and only after my lens stopped working did I find out there was an issue with the DA* 50-135...

I bought my lens brand new in August 2009, so I should be under warranty still, but I haven't talked to Pentax yet.
02-02-2010, 02:18 AM   #72
Veteran Member
PentaxPoke's Avatar

Join Date: Jan 2008
Location: Oklahoma
Posts: 1,411
Original Poster
QuoteOriginally posted by JerryFu Quote
I've just started experiencing this problem in my DA* 50-135. I last used the lens maybe 2 months ago...and when I took it out over the weekend, no autofocus. I think I eliminated all other possibilities, and only after my lens stopped working did I find out there was an issue with the DA* 50-135...

I bought my lens brand new in August 2009, so I should be under warranty still, but I haven't talked to Pentax yet.
Sorry to see my old thread resurrected because of another unfortunate victim. You have experienced "Sometimes Doesn't Move." The only consolation I can give you is that at least it didn't happen to you at a once in a lifetime event (like it did to me.)

Did you notice if you can "wake" the SDM back up by turning the focus and zoom rings, or taking off and replacing the lens, etc?

Eventually the SDM may fail completely like my first one did, after exhibiting this for a while, so you will definitely want to take action so you don't end up with a $1000 MF lens. I recommend the following:

1) Write down the serial number of the lens you have now so you can compare with whatever they send you back.
2) Contact Pentax service (you can do so via email) I think they are reasonably responsive, and you should get a reply in a couple of days. Clearly state the problem in detail, and that you are having intermittent SDM failure. Make sure that they know that sometimes it works, and sometimes it doesn't and you have tested it many different ways. The reason is that if you send it to them, it may choose to work. They send it back to you with a "no service needed" and then it fails later. Also print out the detailed description, and include it in the box you send them with the lens.
3) I was too mad to think of this at the time, but I wish I would have taken video tape of the SDM working intermittently, and then me "waking it up." Is there any way you can do that and post to Youtube or something? It might be useful to others, or Pentax to diagnose for the future.

Good luck.

In case anyone was following this old thread, it was started when my first DA* 50-135 was having problems. When I got my second one, and it started having SDM problems, this thread continued here: https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/81128-more-sup...-problems.html

Last edited by PentaxPoke; 02-02-2010 at 02:35 AM.
02-02-2010, 10:07 AM   #73
New Member




Join Date: Aug 2009
Location: United States
Posts: 19
Thanks for the advice. I didn't have a single problem with this lens before, and I wasn't even aware there was an issue with SDM lenses, until mine stopped working and I started doing some research. I've taken off and put back on the lens numerous times, played around with the zoom and focus rings, toggled the AF/MF switch...all to no avail. My lens has not budged since I started trying to use it over the weekend. I have two other prime lenses that work without a hitch though...
02-02-2010, 10:15 AM   #74
Veteran Member




Join Date: Jan 2009
Location: Canada
Posts: 1,255
QuoteOriginally posted by JerryFu Quote
Thanks for the advice. I didn't have a single problem with this lens before, and I wasn't even aware there was an issue with SDM lenses, until mine stopped working and I started doing some research. I've taken off and put back on the lens numerous times, played around with the zoom and focus rings, toggled the AF/MF switch...all to no avail. My lens has not budged since I started trying to use it over the weekend. I have two other prime lenses that work without a hitch though...
Many people on the forum--including me--find the SDM motor dead, after taking the lens out of storage. It's very odd.
02-02-2010, 01:32 PM   #75
New Member




Join Date: Aug 2009
Location: United States
Posts: 19
I talked with Pentax support over chat, and the solution was to send my lens in, of course. I took a picture of the serial number on the lens, so I'll keep everything documented.

I brought up the fact that I read that a lot of people were having this problem with SDM lenses, and the lady told me that there was an issue that happened with older cameras. I have a K-7 though...and although all these reports of problems doesn't represent those who haven't had issues, it does seem like there is something going on...
Reply

Bookmarks
  • 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!
auto, bag, bit, da*, da* 50-135mm, focus, k-mount, k20d, lens, pentax lens, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Problem with new old Mamiya 135mm 2.8 Ira Pentax SLR Lens Discussion 4 08-09-2010 09:09 AM
DA*50-135mm f2.8 SDM Problems / No Problem rustynail925 Pentax SLR Lens Discussion 30 03-22-2010 06:08 PM
Help - Infinity focus problem with DA* 50-135mm 2.8 chickentender Pentax SLR Lens Discussion 9 08-06-2009 10:20 PM
Pentax 50-135mm Vignetting Problem? nah Pentax SLR Lens Discussion 6 04-15-2009 11:55 AM
Problem with the 50-135mm DA* offertonhatter Pentax SLR Lens Discussion 15 03-01-2009 09:53 PM



All times are GMT -7. The time now is 12:06 PM. | See also: NikonForums.com, CanonForums.com 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?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top