A possible broken SDM on a brand new 16-50

SOldBear · 06-24-2011, 11:24 AM

Apparently the lens is bad. Interestingly, the symptom you describe is very similar to the case of a 7-contact TC (or extension tube) used in combination with a DA* zoom lens.

Please read the last part of this post.

RossCo · 06-24-2011, 01:51 PM

I had a similar problem with my 16-50. It was my first autofocus lens and I had heard that they were not a fast focusing so I accepted the fact that it was a manual focus lens. I then bought a 60-250 and the autofocus was very fast so I took the lens back to where I bought it and they sent it back to Pentax Canada. About 10 weeks later I got the same lens back but they had replaced all of the motors. It now focuses as fast as the 60-250.

Paul

pxpaulx · 06-24-2011, 02:23 PM

Are any other lenses NOW working on your K-7? I was wondering if you put the lens on while the camera was powered on. Is it possible the contacts were shorted? I don't know if that is possible, but if the power was on and somehow the contacts were reversed or something...it does sound like some sort of signal problem, rather than the typical straight failure most experience.

desc4d · 06-24-2011, 09:06 PM

Hi guys, thanks for the replies.

SOldBear, really interesting stuff, although I'm reading the whole thread so I'm yet to finish it.

Pxpaulx, other lenses focus without any problem, I've seen in some forums that issue about the contacts getting shorted so I was careful the first time I mounted the lens.
To me it sounds as well as a signal problem, kind of what SOldBear has in the thread he pointed out, so in this case a replacement seems the only viable option by now.

The guys from pentax said that it's most likely a problem with the lens itself rather than the camera, so we'll see when I get the new one if it has been sorted out.

Thanks and have a nice weekend.

Daniel

pxpaulx · 06-25-2011, 02:42 PM

Good luck, sounds like the lens to me as well - make sure to update results with the replacement!

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06-24-2011, 11:24 AM	#16
SOldBear Veteran Member Join Date: Feb 2009 Location: Alameda, CA Posts: 3,206	Apparently the lens is bad. Interestingly, the symptom you describe is very similar to the case of a 7-contact TC (or extension tube) used in combination with a DA* zoom lens. Please read the last part of this post.

06-24-2011, 01:51 PM	#17
RossCo Forum Member Join Date: Aug 2009 Location: Victoria, British Columbia, Canada Photos: Gallery \| Albums Posts: 53	I had a similar problem with my 16-50. It was my first autofocus lens and I had heard that they were not a fast focusing so I accepted the fact that it was a manual focus lens. I then bought a 60-250 and the autofocus was very fast so I took the lens back to where I bought it and they sent it back to Pentax Canada. About 10 weeks later I got the same lens back but they had replaced all of the motors. It now focuses as fast as the 60-250. Paul

06-24-2011, 02:23 PM	#18
pxpaulx Veteran Member Join Date: May 2009 Location: Twin Cities, MN Posts: 2,867	Are any other lenses NOW working on your K-7? I was wondering if you put the lens on while the camera was powered on. Is it possible the contacts were shorted? I don't know if that is possible, but if the power was on and somehow the contacts were reversed or something...it does sound like some sort of signal problem, rather than the typical straight failure most experience.

06-24-2011, 09:06 PM	#19
desc4d New Member Join Date: Apr 2011 Location: Quito, Ecuador Posts: 11 Original Poster	Hi guys, thanks for the replies. SOldBear, really interesting stuff, although I'm reading the whole thread so I'm yet to finish it. Pxpaulx, other lenses focus without any problem, I've seen in some forums that issue about the contacts getting shorted so I was careful the first time I mounted the lens. To me it sounds as well as a signal problem, kind of what SOldBear has in the thread he pointed out, so in this case a replacement seems the only viable option by now. The guys from pentax said that it's most likely a problem with the lens itself rather than the camera, so we'll see when I get the new one if it has been sorted out. Thanks and have a nice weekend. Daniel

06-25-2011, 02:42 PM	#20
pxpaulx Veteran Member Join Date: May 2009 Location: Twin Cities, MN Posts: 2,867	Good luck, sounds like the lens to me as well - make sure to update results with the replacement!