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03-14-2013, 10:44 AM   #1
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What Indicates SDM failure?

a simple question that would seem to have a simple answer...sdm failure should mean the lens stops focusing (right?)...my da300 (which i love) seems to be progressing to sdm failure land...i hope i am wrong...sometimes it focuses normally and other times it seems to sit there for a few seconds before it decides to try to focus...it doesn't sqeak like some have mention...it makes no sound at all but i am losing confidence that i will be able to get the focus i need on birds because it may or may not focus when i need it to...will the lens eventually just die or go on with this periodic work not work situation...it is outside pentax warranty but got square trade on every sdm lens i own cause i didn't want to take any chances...this one might pay for itself

03-14-2013, 10:59 AM - 1 Like   #2
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Simply and not sarcastically put...the lens doesn't auto focus, period. It just won't move. I've had it happen on my DA*16-50 and that was it. It just didn't work any more. On my DA*55 it was a bit different, it was sluggish at first, almost like it needed to warm up. It never really stopped working but it didn't like to start working either.
03-14-2013, 11:01 AM   #3
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It's not sounding too good.

Is it not worth getting repaired now before it goes totally phutt, in case it's something minor or stupid, rather than full blown failure.
03-14-2013, 11:01 AM   #4
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Do the firmware hack to get it to go to screwdrive and be done with it.

03-14-2013, 11:30 AM   #5
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QuoteOriginally posted by kerrowdown Quote
It's not sounding too good.

Is it not worth getting repaired now before it goes totally phutt, in case it's something minor or stupid, rather than full blown failure.
my fear is i send it off and it decides to work for the period it is on the shop


QuoteOriginally posted by snake Quote
Do the firmware hack to get it to go to screwdrive and be done with it.
i have seen that others have done this...i am curious how they felt the lens performed before and after
03-14-2013, 12:16 PM   #6
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Pro:
• cheaper than (repeated) repairs
• trouble free, with little chance of dying in the field when you need it

Con:
• loud
• intimidating update process

Awash:
• focus speed is about the same
• SDM is known to have better accuracy than screwdrive, but I've never noticed
03-14-2013, 12:24 PM   #7
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Sometimes, a low battery level may adversely affect the SDM function as I have noticed that in the past. Just sayin...
03-14-2013, 02:45 PM   #8
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Amy,

I don't get your same symptoms very often with my DA*300, but do once in a while. I do get it more often with my DA*16-50. We had a similar conversation a few months ago, and I was just writing it off to a low contrast situation where the lens just didn't want to start focusing. I'm looking into this further now because of a related possible problem with my K-5.

First thing to try - when the lens doesn't' want to start focusing as you describe, switch to live mode and see if it will move. I've found that every time I did this, to focus motor did in fact kick right in. So in my opinion, that proves there is nothing wrong with the SDM drive,

Now on to the next part - I've been having a problem lately that I had with my previous K-5. After about 6 months use, it seems my lenses all of a sudden need a fine AF adjustment. Where they all were fine with no AF adjustment for the first 6 months, they all now need adjustment mostly on the positive side. It seems the AF mechanism is shifting on its own.

So then you ask what does this have to do with the SDM lenses not starting to focus? I don't know yet, but I am beginning to think there might be a connection here. Especially if the lenses start focusing properly in live mode.

For the record, I am doing this testing on all DA* lenses with SDM. My K-5 is on its way to CRIS right now with a detailed description of these problems along with graphs of the inconsistency of auto focus. I bought a piece of software that not only graphs the AF adjustments to make a perfect fine tune, but also graphs auto focus inconsistency on a graph. I am wondering if this AF problem is also causing the SDM lenses to not start properly.

03-14-2013, 03:11 PM   #9
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QuoteOriginally posted by Aegon Quote
Pro:
• cheaper than (repeated) repairs
• trouble free, with little chance of dying in the field when you need it

Con:
• loud
• intimidating update process

Awash:
• focus speed is about the same
• SDM is known to have better accuracy than screwdrive, but I've never noticed
+con
* might damage the lens more.

It's known that some AF malfunctions are due to a misalgiment with a shaft, if that's the case then further using the AF with screwdrive might damage it more.
03-14-2013, 03:21 PM   #10
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QuoteOriginally posted by Anvh Quote
+con
* might damage the lens more.

It's known that some AF malfunctions are due to a misalgiment with a shaft, if that's the case then further using the AF with screwdrive might damage it more.
So in this case, the lens needs to be repaired anyhow, so it's not like there's going to be more broken, since ALL of that stuff is going to be pulled and replaced anyhow.
03-14-2013, 04:39 PM   #11
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DA* 50-135mm failure

In January 2013, my 1-year old DA* 50-135mm was repaired under warranty by Pentax Canada. It was showing the following issues on a K-5:


1. Frequently, the lens would not autofocus for several minutes after being mounted on the camera and the camera turned on. Autofocus would function after the camera had sat turned on for several minutes, the focus ring was exercised manually several times between infinity and MFD, and the camera AF button or shutter release was pressed numerous times. It seemed that the lens needed to “wake up” after not being used for a day or longer. The problem occurred regardless of battery state of charge or focal length setting.

2. Frequently, the lens would not lock focus at long focal lengths, typically at or near 135mm, regardless of target distance or target type (including high contrast ‘easy’ targets). The lens would 'stutter' 2-3 times on either side of the supposed focus point, but the camera would not lock or confirm focus.


3. After autofocusing correctly, the manual ‘quick shift’ focus mechanism would occasionally seize – manual focusing was not possible towards one side of the locked focus point. It seemed that something was jamming or blocking the focus mechanism.


The service notes from Pentax Canada indicated: "Motor has been replaced. Unit has been adjusted, cleaned and tested."


I was very satisfied with the turnaround time by Pentax Canada. The lens works well now.


- Craig
03-14-2013, 06:06 PM   #12
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QuoteOriginally posted by aleonx3 Quote
Sometimes, a low battery level may adversely affect the SDM function as I have noticed that in the past. Just sayin...
the battery was on full charge
03-14-2013, 06:13 PM   #13
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QuoteOriginally posted by stormtech Quote
Amy,

I don't get your same symptoms very often with my DA*300, but do once in a while. I do get it more often with my DA*16-50. We had a similar conversation a few months ago, and I was just writing it off to a low contrast situation where the lens just didn't want to start focusing. I'm looking into this further now because of a related possible problem with my K-5.

First thing to try - when the lens doesn't' want to start focusing as you describe, switch to live mode and see if it will move. I've found that every time I did this, to focus motor did in fact kick right in. So in my opinion, that proves there is nothing wrong with the SDM drive,

Now on to the next part - I've been having a problem lately that I had with my previous K-5. After about 6 months use, it seems my lenses all of a sudden need a fine AF adjustment. Where they all were fine with no AF adjustment for the first 6 months, they all now need adjustment mostly on the positive side. It seems the AF mechanism is shifting on its own.

So then you ask what does this have to do with the SDM lenses not starting to focus? I don't know yet, but I am beginning to think there might be a connection here. Especially if the lenses start focusing properly in live mode.

For the record, I am doing this testing on all DA* lenses with SDM. My K-5 is on its way to CRIS right now with a detailed description of these problems along with graphs of the inconsistency of auto focus. I bought a piece of software that not only graphs the AF adjustments to make a perfect fine tune, but also graphs auto focus inconsistency on a graph. I am wondering if this AF problem is also causing the SDM lenses to not start properly.
stan i had a similar thing happen to both my k5s about 6-9 months ago...they were rock solid at 0 for all lens...the older one suddenly jumped to 7+ for all lens and pretty much has stayed there...the newer one by 9 months did it shortly thereafter at 5+...i wondered if it had anything to do with the weather getting colder but cameras have pretty much stayed the same and all my lens fine on both cameras...i thought maybe i had forgotten how the 300 should act (cause i had been using the 500 alot) so i threw on the 60-250 and it focused immediately which reinforced the 300 was the issue...i will be curious what pentax says anout your camera...i am holding off as long as possible but im very close to pulling the trigger on the 300...i also don't think i can modify it because i don't want to screw up my square trade warranty...so for now i will hang tight and try to use it more and check out some of your suggestions...maybe this weekend...thanks all!!!
03-14-2013, 06:27 PM   #14
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QuoteOriginally posted by pearsaab Quote
stan i had a similar thing happen to both my k5s about 6-9 months ago...they were rock solid at 0 for all lens...the older one suddenly jumped to 7+ for all lens and pretty much has stayed there...the newer one by 9 months did it shortly thereafter at 5+...i wondered if it had anything to do with the weather getting colder but cameras have pretty much stayed the same and all my lens fine on both cameras...i thought maybe i had forgotten how the 300 should act (cause i had been using the 500 alot) so i threw on the 60-250 and it focused immediately which reinforced the 300 was the issue...i will be curious what pentax says anout your camera...i am holding off as long as possible but im very close to pulling the trigger on the 300...i also don't think i can modify it because i don't want to screw up my square trade warranty...so for now i will hang tight and try to use it more and check out some of your suggestions...maybe this weekend...thanks all!!!
Not that it is good, but it's nice to hear I'm not the only one having the same symptoms with the K-5. I literally spent days testing with half the time thinking I was off my rocker or my eyes were getting really bad.

I did have the same thing happen to a previously owned K-5 - came back from CRIS saying "adjust auto focus to factory specs" and it was right on after that.

If your 300 is under warranty, why not just send it in for evaluation? Actually I am very close to the time of year when I will really start using my gear a lot (once it warms up). The turn around for sending my K-5 in was 2 weeks total - 3 days shipping to Az, 2 days in the shop, then 6 days return shipping (UPS). The only problem you might encounter with a repair on your 300 is if they have to wait for parts from Japan - then it might turn out to a 2-3 month ordeal.

At any rate, I will let you know when I get this one back and the results - hopefully within 2 weeks or I might have to break down and buy a K-5 IIS.............
03-15-2013, 01:39 AM   #15
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QuoteOriginally posted by snake Quote
So in this case, the lens needs to be repaired anyhow, so it's not like there's going to be more broken, since ALL of that stuff is going to be pulled and replaced anyhow.
Yeah but with the first you've warranty with the hack you loose everything.

Here in the EU you can make an appeal that a product shouldn't fail that fast so you have extended warranty.
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