DA*16-50 SDM and MF failure???

Phii Mii · 06-07-2013, 07:30 PM

SDM gave up on this lens a couple of days ago. I knew this would probably happen some day but I thought I'd still be able to focus manually. Is this a typical SDM failure that also MF will not work? I turn the focus ring and nothing happens.

When i use the lens on my old 135-film camera the screw drive AF works without any problem (but not MF).

Last edited by Phii Mii; 06-07-2013 at 11:33 PM.

Eulogy · 06-07-2013, 08:33 PM

Sounds like the MF/AF clutch used for quick shift has broken perhaps? Seems like a repair job is in order...

Alternatively, look at the guide to convert it to screw driven AF if you'd like.

Steinback · 06-07-2013, 08:47 PM

Manual focus should still work; it does sound like something is jammed beyond the regular SDM motor failure. There is a repair guide on here for taking apart the back of the lens and freeing up the SDM motor with a screwdriver but I don't know if that will take care of whatever else may be wrong.

If you have an older camera body like the K10d or K20d the screwdrive conversion process is pretty easy - it took me about 5 minutes since my camera was already running in developer mode. My SDM motor still works but I was curious to compare it to screw drive, which is nosier but otherwise similar in speed and accuracy.

Phii Mii · 06-07-2013, 11:38 PM

I'd prefer it without AF but still with MF. I'll check how much it would cost to fix the MF since AF isn't important.

Anvh · 06-08-2013, 05:07 AM

Pentax have said that one of the causes of the AF failing with this lens is due to a misalingment with on of th shafts.
First time hearing that MF also actually stop working but seems to comfirm it can happen.

Don't know where you live but maybe you can force extra warranty from Pentax, if there is no external damage to the lens or something like that.

kyc · 06-08-2013, 06:29 AM

I had this symptom on my 60-250 twice, where the SDM stopped working and I couldn't get MF to work (the focus ring turned but the gear seemed to have been disengaged). The first time lasted for a while and by playing with MF I eventually got the lens fully working. A few months later, I had the same issue by for a much shorter time. Since then, no problems.

What I noticed about the two instances was that I was out in the summer sun using the lens for a lengthy period, so I suspect it may be heat related.

ve2vfd · 06-08-2013, 06:33 AM

The AF died twice on my DA*16-50...

The first time the AF died (within 90 days of buying the lens) the manual focus was still working.

The second time the AF died (1.5 years after buying it), the manual focus ring no longer worked at all and they had to change the MF clutch and AF motor.

Pat

Phii Mii · 07-06-2013, 09:01 AM

Originally posted by Phii Mii

SDM gave up on this lens a couple of days ago. I knew this would probably happen some day but I thought I'd still be able to focus manually. Is this a typical SDM failure that also MF will not work? I turn the focus ring and nothing happens.

When i use the lens on my old 135-film camera the screw drive AF works without any problem (but not MF).

Update: The SDM and the quick shift is working fine again. I didn't use the lens for a few weeks and was going to send it o be repaired but wanted to test it once before and this time it worked fine

By the way, when it stopped working I was laying on my back and taking photos through the tree tops. Maybe to heavy for the SDM motor?

K57XR · 07-06-2013, 09:33 AM

Originally posted by Phii Mii

Update: The SDM and the quick shift is working fine again. I didn't use the lens for a few weeks and was going to send it o be repaired but wanted to test it once before and this time it worked fine

By the way, when it stopped working I was laying on my back and taking photos through the tree tops. Maybe to heavy for the SDM motor?

Good to hear your lens is working again however; it shouldn't do what it did regardless. I'd suggest sending it in for repair/checkup nonetheless. Good luck.

06-07-2013, 07:30 PM	#1
Phii Mii Junior Member Join Date: Oct 2012 Posts: 27	*DA16-50 SDM and MF failure???** SDM gave up on this lens a couple of days ago. I knew this would probably happen some day but I thought I'd still be able to focus manually. Is this a typical SDM failure that also MF will not work? I turn the focus ring and nothing happens. When i use the lens on my old 135-film camera the screw drive AF works without any problem (but not MF). Last edited by Phii Mii; 06-07-2013 at 11:33 PM.

06-08-2013, 06:29 AM	#6
kyc Forum Member Join Date: Sep 2009 Photos: Gallery \| Albums Posts: 69	*Similar occurrence on DA 60-250** I had this symptom on my 60-250 twice, where the SDM stopped working and I couldn't get MF to work (the focus ring turned but the gear seemed to have been disengaged). The first time lasted for a while and by playing with MF I eventually got the lens fully working. A few months later, I had the same issue by for a much shorter time. Since then, no problems. What I noticed about the two instances was that I was out in the summer sun using the lens for a lengthy period, so I suspect it may be heat related.

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06-07-2013, 08:33 PM	#2
Eulogy Veteran Member Join Date: Feb 2012 Location: Fredericton, New Brunswick Photos: Gallery Posts: 632	Sounds like the MF/AF clutch used for quick shift has broken perhaps? Seems like a repair job is in order... Alternatively, look at the guide to convert it to screw driven AF if you'd like.

06-07-2013, 08:47 PM	#3
Steinback Veteran Member Join Date: Jan 2008 Location: GTA, ON, Canada Photos: Gallery \| Albums Posts: 1,673	Manual focus should still work; it does sound like something is jammed beyond the regular SDM motor failure. There is a repair guide on here for taking apart the back of the lens and freeing up the SDM motor with a screwdriver but I don't know if that will take care of whatever else may be wrong. If you have an older camera body like the K10d or K20d the screwdrive conversion process is pretty easy - it took me about 5 minutes since my camera was already running in developer mode. My SDM motor still works but I was curious to compare it to screw drive, which is nosier but otherwise similar in speed and accuracy.

06-07-2013, 11:38 PM	#4
Phii Mii Junior Member Join Date: Oct 2012 Posts: 27 Original Poster	I'd prefer it without AF but still with MF. I'll check how much it would cost to fix the MF since AF isn't important.

06-08-2013, 05:07 AM	#5
Anvh Veteran Member Join Date: Sep 2011 Posts: 4,616	Pentax have said that one of the causes of the AF failing with this lens is due to a misalingment with on of th shafts. First time hearing that MF also actually stop working but seems to comfirm it can happen. Don't know where you live but maybe you can force extra warranty from Pentax, if there is no external damage to the lens or something like that.

06-08-2013, 06:33 AM	#7
ve2vfd Veteran Member Join Date: Aug 2007 Location: Montreal, Canada Photos: Gallery Posts: 2,433	The AF died twice on my DA*16-50... The first time the AF died (within 90 days of buying the lens) the manual focus was still working. The second time the AF died (1.5 years after buying it), the manual focus ring no longer worked at all and they had to change the MF clutch and AF motor. Pat

07-06-2013, 09:01 AM	#8
Phii Mii Junior Member Join Date: Oct 2012 Posts: 27 Original Poster	Originally posted by Phii Mii SDM gave up on this lens a couple of days ago. I knew this would probably happen some day but I thought I'd still be able to focus manually. Is this a typical SDM failure that also MF will not work? I turn the focus ring and nothing happens. When i use the lens on my old 135-film camera the screw drive AF works without any problem (but not MF). Update: The SDM and the quick shift is working fine again. I didn't use the lens for a few weeks and was going to send it o be repaired but wanted to test it once before and this time it worked fine By the way, when it stopped working I was laying on my back and taking photos through the tree tops. Maybe to heavy for the SDM motor?

07-06-2013, 09:33 AM	#9
K57XR Veteran Member Join Date: Feb 2011 Location: Colorado, USA Posts: 830	Originally posted by Phii Mii Update: The SDM and the quick shift is working fine again. I didn't use the lens for a few weeks and was going to send it o be repaired but wanted to test it once before and this time it worked fine By the way, when it stopped working I was laying on my back and taking photos through the tree tops. Maybe to heavy for the SDM motor? Good to hear your lens is working again however; it shouldn't do what it did regardless. I'd suggest sending it in for repair/checkup nonetheless. Good luck.