DA*50-135 SDM problem.


Status
Not open for further replies.

skypacker

New Member
Oct 18, 2006
848
0
0
#1
My DA*50-135 had been behaving erratically, refusing to AF-C and often refusing to lock focus with AF-S too, even under excellent high contrast situations.

It was also making squeaking noises sometimes when hunting for focus.

It's still under warranty, so gave it to Kevin for a checkup last week, and today, I learned that it has gone to Japan for repairs. It will be 4 weeks before I get it back:(

There are quite a few failures reported on DPreview for both the 16-50 and 50-135. The 300 and 200 primes seem to be relatively immune so far.

Anyone here have problems with their SDM lenses?
 

#2
Thats the problem with built motor... like it or not, sooner or later the motor will fail, regardless of lens... even for other brands same thing... thats why i avoided as much as possible to get a normal lens with no built in motor. Its not like cars where u can service it once a while, even with that doesn't mean cars won't break down... the lens motor have finite lifetime, times up it goes, and usually the repair cost is quite costly... hope u get ur lens back asap... :)
 

skypacker

New Member
Oct 18, 2006
848
0
0
#3
Yeah, apparently pentax use the cheap micromotor drives instead of the more expensive but also more reliable ring type USM drive for the DA* lenses.

I hope I get it back within 4 weeks, as the 50-135 was my 'main' lens.:(
 

istDeS

Senior Member
Dec 7, 2005
4,249
10
0
"River end"
#4
I assume it is the built-in supersonic motor that is causing the problem. It works fine with the drive screw?

My pair no problem so far..I don't know when it will fail but the failing of built-in supersonic motor is what one might face when getting the DA* lens.:sweat:
 

scorpioh

New Member
Jul 17, 2007
1,973
0
0
Woodlands
#5
That's one of the reasons why I don't invest in BIM lenses.They are more like some utility product with a rather limited lifetime rather than some gems u can appreciated through your life-time.
 

Last edited:

Ben Loke

New Member
Aug 26, 2004
1,060
0
0
Guilin
#6
My DA*50-135 had been behaving erratically, refusing to AF-C and often refusing to lock focus with AF-S too, even under excellent high contrast situations.

It was also making squeaking noises sometimes when hunting for focus.

It's still under warranty, so gave it to Kevin for a checkup last week, and today, I learned that it has gone to Japan for repairs. It will be 4 weeks before I get it back:(

There are quite a few failures reported on DPreview for both the 16-50 and 50-135. The 300 and 200 primes seem to be relatively immune so far.

Anyone here have problems with their SDM lenses?
My pair of DA*16-50 & *50-135 are so far so good and if (touch wood) the motor fails, I may have to go subsonic.

BTW, where did you bought your lens?

I bought my DA*16-50mm in Japan and the *50-135 at AP.
 

skypacker

New Member
Oct 18, 2006
848
0
0
#7
I assume it is the built-in supersonic motor that is causing the problem. It works fine with the drive screw?

My pair no problem so far..I don't know when it will fail but the failing of built-in supersonic motor is what one might face when getting the DA* lens.:sweat:
Yes, it focuses properly with the screw-drive on a K100D, as tested by Kevin and me.
I felt that the screw-drive focusing was actually faster than SDM on the K20D, but it could be my imagination;p:bsmilie:

Problem is, on the K20D, there is no option to select screw-drive for SDM lenses that have both. It's either SDM or nothing. Very stupid move by Pentax..they could have added a simple menu option to select the drive type via a firmware update.:thumbsd:
 

skypacker

New Member
Oct 18, 2006
848
0
0
#8
My pair of DA*16-50 & *50-135 are so far so good and if (touch wood) the motor fails, I may have to go subsonic.

BTW, where did you bought your lens?

I bought my DA*16-50mm in Japan and the *50-135 at AP.

My 50-135 was bought on April 19, 2008 from MS Color. Luckily, it's still under warranty.

I bought my 16-50 just last week from AP-F.
I haven't even tested it properly for corner softness or other issues due to lack of time...taken maybe 20 shots with it so far and all in lousy weather:(

I hope to take it out tomorrow and test it out for IQ etc.
 

skypacker

New Member
Oct 18, 2006
848
0
0
#9
That's one of the reasons why I don't invest in BIM lenses.They are more like some utility product with a rather limited lifetime rather than some gems u can appreciated through your life-time.
The 50-135 is one of the finest Pentax DA lenses. Every Pentaxian, especially those with the 10mp or higher sensors should own one. It's IQ, ergonomics etc are top-notch.:)

It's Achilles' Heel seems to be the cheapo motors which Pentax put in.
 

fengwei

Moderator
Staff member
Aug 25, 2004
14,462
12
0
Queenstown
www.pbase.com
#10
Problem is, on the K20D, there is no option to select screw-drive for SDM lenses that have both. It's either SDM or nothing. Very stupid move by Pentax..they could have added a simple menu option to select the drive type via a firmware update.:thumbsd:
Actually you still can use the lens as non-SDM one on your K20D, just put something between the two small brass plates at the mounting and the matching ones on the camera body so to disconnect them, your camera would recognize the lens as a non-SDM one ;) Or if you dare, just bend the two plates a bit (inwards) so they won't touch the matching ones on the body :D

BTW, sorry to hear about the problem. That's one thing I'm afraid too. My FA*2870 and 80200 got PowerZoom motors inside the lens barrels too, and that thing was reported to stop working by some users as well. Luckily mine still work great ever after over 10 to 15 years of service :cool:

Don't worry, your lens will be as good as new when it comes back.
 

scorpioh

New Member
Jul 17, 2007
1,973
0
0
Woodlands
#11
The 50-135 is one of the finest Pentax DA lenses. Every Pentaxian, especially those with the 10mp or higher sensors should own one. It's IQ, ergonomics etc are top-notch.:)

It's Achilles' Heel seems to be the cheapo motors which Pentax put in.
I do agree that its got one of the best optical quality for a zoom.
 

kkleong

New Member
Jan 21, 2005
190
0
0
In The Wilderness
#12
My DA*50-135 had been behaving erratically, refusing to AF-C and often refusing to lock focus with AF-S too, even under excellent high contrast situations.

It was also making squeaking noises sometimes when hunting for focus.

It's still under warranty, so gave it to Kevin for a checkup last week, and today, I learned that it has gone to Japan for repairs. It will be 4 weeks before I get it back:(

There are quite a few failures reported on DPreview for both the 16-50 and 50-135. The 300 and 200 primes seem to be relatively immune so far.

Anyone here have problems with their SDM lenses?
Sorry to hear about your lens bro :(
Is it due to often not powering off when swapping lenses?
Just wondering about the cause. If it is, Pentax should at least cater for such a safety "feature".
I think Pentax should also come out with a new firmware (ie. SDM-support cam, ex. K100Super, K10, K200, K20) to select SDM or camera-driven.
Otherwise, the SDM lens will become a white elephant when encountered problem :dunno:
 

istDeS

Senior Member
Dec 7, 2005
4,249
10
0
"River end"
#13
Sorry to hear about your lens bro :(
Is it due to often not powering off when swapping lenses?
Just wondering about the cause. If it is, Pentax should at least cater for such a safety "feature".
I think Pentax should also come out with a new firmware (ie. SDM-support cam, ex. K100Super, K10, K200, K20) to select SDM or camera-driven.
Otherwise, the SDM lens will become a white elephant when encountered problem :dunno:
It will be a nice additional feature to power on/off the SDM with the camera. Anyway, to overcome the problem, just put something between the two small brass plates to disconnect the SDM as what fengwei metioned earlier or downgrade to a body without SDM support.:bsmilie:
 

Gengh

New Member
May 6, 2007
1,984
0
0
Florida
#14
Oh, skypacker, so that other 50-135 belongs to you! I just sent mine in on 20 Feb 'cos my SDM frequently refuses to work when the lens is first mounted onto the body. After a minute or so of "warmup" by constantly trying to make it AF, the SDM will suddenly come to life and everything will be ok for the next few hours. It squeaks also when focusing, but I don't have problems getting the AF to lock.

I wanted to keep the lens till this coming week before sending it in, but Kevin told me that he had another 50-135 to be shipped to Japan real soon, and he didn't know when he'll make another shipment, so I resigned myself to not having the lens during my trip last week.

Anyway, he told me that it seems like it's mainly the first batch of 50-135 that has this SDM problems, not sure how to identify which batch the lens belongs to though. My 16-50 is still in tip-top condition, hope it stays that way.
 

skypacker

New Member
Oct 18, 2006
848
0
0
#15
Fengwei, bypassing the SDM was one option, but since the lens is still under warranty, I thought I'd make sure everything works as it's supposed to and the SDM is back to working condition. I don't want problems down the line after the warranty expires.:sweat:

Sorry to hear about your lens bro :(
Is it due to often not powering off when swapping lenses?
Nope, i always power off the camera before swapping lenses, whether screw-drive or SDM.
But you are right, changing SDM lenses with the camera powered on seems to lead to problems, if we are to go by DPreview forum reports.
 

skypacker

New Member
Oct 18, 2006
848
0
0
#16
Oh, skypacker, so that other 50-135 belongs to you! I just sent mine in on 20 Feb 'cos my SDM frequently refuses to work when the lens is first mounted onto the body. After a minute or so of "warmup" by constantly trying to make it AF, the SDM will suddenly come to life and everything will be ok for the next few hours. It squeaks also when focusing, but I don't have problems getting the AF to lock.

I wanted to keep the lens till this coming week before sending it in, but Kevin told me that he had another 50-135 to be shipped to Japan real soon, and he didn't know when he'll make another shipment, so I resigned myself to not having the lens during my trip last week.

Anyway, he told me that it seems like it's mainly the first batch of 50-135 that has this SDM problems, not sure how to identify which batch the lens belongs to though. My 16-50 is still in tip-top condition, hope it stays that way.
Yeah, that one is mine:D
Kevin did mention another 50-135 having a problem, but that was supposed to be one purchased outside SG. Is that the same as yours, or are there 3 problem-prone 50-135s around now?

Since you don't have the lens with you, it's not possible to test, otherwise I'd have asked you to check out the AF-C for possible symptoms similar to mine. In my case too, at times, AF-S wouldn't lock, and a few power off/on cycles later, it would behave normally. Sometimes, it just stubbornly refused to lock regardless of anything I tried.

AF-C was highly erratic almost all the time for the couple of days before I sent it in...wouldn't lock on even a slow-moving 747 near Changi in bright evening sunlight (previously, it had no trouble doing so).

Anyway, let's hope we get our lenses back soon, and as good as new:thumbsup:

I really miss the 50-135 but on the other hand, I have the new 16-50 to play with for now, and the weather is generally not too good either these afternoons for outdoor shooting.
 

Gengh

New Member
May 6, 2007
1,984
0
0
Florida
#17
Yeah, that one is mine:D
Kevin did mention another 50-135 having a problem, but that was supposed to be one purchased outside SG. Is that the same as yours, or are there 3 problem-prone 50-135s around now?

Since you don't have the lens with you, it's not possible to test, otherwise I'd have asked you to check out the AF-C for possible symptoms similar to mine. In my case too, at times, AF-S wouldn't lock, and a few power off/on cycles later, it would behave normally. Sometimes, it just stubbornly refused to lock regardless of anything I tried.

AF-C was highly erratic almost all the time for the couple of days before I sent it in...wouldn't lock on even a slow-moving 747 near Changi in bright evening sunlight (previously, it had no trouble doing so).

Anyway, let's hope we get our lenses back soon, and as good as new:thumbsup:

I really miss the 50-135 but on the other hand, I have the new 16-50 to play with for now, and the weather is generally not too good either these afternoons for outdoor shooting.
Purchased outside SG? No then that's not me, mine has its origins from CP. I was thinking the same thing as you, I don't die die need the SDM, but it's irritating to know that there's something wrong with the lens. Since it's under warranty, I should make sure everything's working fine.

I almost never use AF-C, so I can't say if I have the same AF-C problem as you. But my AF-S symptoms are different from yours, when first mounted, the focusing mechanism moves very very slowly for the first minute or so (turning a very small step every 1 second or so), before it suddenly picks up the energy to focus normally. AF locking was not a problem, as long as it could actually get there!

I shoot mostly with the 16-50, but I still find that the 50-135 gives better results when I use it. Let's wait eagerly together for good news from Kevin!
 

skypacker

New Member
Oct 18, 2006
848
0
0
#18
Gengh,
saw your post in the photos thread, but don't want to carry on an OT conversation there, so replying here:
Yes, Kevin called me yesterday afternoon to advise that my 50-135 too has returned from its Japanese vacation. I will collect it on Friday :)

Have you picked up yours? How is it now?
 

Gengh

New Member
May 6, 2007
1,984
0
0
Florida
#19
I'm thinking of going to pick it up tomorrow first thing in the morning, then I can use it on Sat for the outing. Are you going in the morning too?
 

skypacker

New Member
Oct 18, 2006
848
0
0
#20
I'm thinking of going to pick it up tomorrow first thing in the morning, then I can use it on Sat for the outing. Are you going in the morning too?
I'll go in the afternoon, probably after 1300h; I have to be at work in the morning.
Will post back if everything is alright with the lens. It should be all okay now since the SDM was apparently replaced in Japan.
 

Status
Not open for further replies.
Top Bottom