Originally posted by aleonx3 I use the two lenses (DA*16-50 and DA*50-135) a lot for event photography. Both lenses are great IQwise, and both lenses have been replaced with newer SDM motors and still functioning today. In the early introduction of the lenses, some people had de-centering problems with the DA*16-50. There are times that I thought I might have that problem especially with the 16-50 lens, and I find it hard to test that particular problem especially if the problem is slight and not so obvious. In any case, if you encounter such a problem with the new lens you should be able to get it corrected within the warranty period.
One thing I noticed that the price of the new DA* 16-50/50-135 have gone up a lot since the early introduction year. So, I guess it pays to be an early adopter in this case despite the problems we encountered initially.
It's good to use them a lot. One assumptions that my friends made according to observations from Pentax users in Thailand is that the SDM problem trends to occur in rarely used lenses, sitting on the shelf rather than being used. It seems like the lubricant in SDM motor last longer when it moves. And it gets dry when the lens just stays still.
I'm not sure about this but it looks like it.
Originally posted by Adam There haven't been many complaints about failures in the part year. If there were issues, we would have seen lots of threads, as hundreds of 16-50s were sold last fall to our members (during the black Friday sale)
It could be from many reasons. It could be because it's not the time yet? Or they are frustrated to complain? Or they barely use it so they still don't detect it? Or all lenses were already well redesigned?
In my opinion it's still mystery. Even there is 1 year warranty, what if the SDM fails after 1 year?
So, it would be really great if Ricoh just officially announce that they have fixed this problem already. That can rise our confident to spend money for these premium lenses.