Another bad 16-50...

[jtb04a]

Did your new one work better?

[surferboy36O]

I have the 17-70mm f4, pretty good lens!

[tenggilingbocor]

that is happen because you didnt turn the switch on the lens to MF..

[inferno10]

@tenggilingbocor Cameras that lack the Quick Shift mechanism do require you to switch the camera's AF switch to M in order to physically decouple the screw motor from the lens' focusing shaft. However, the DA* 16-50 f/2.8 has the Quick Shift mechanism. By design, it's supposed to let you freely rotate the focus ring after focusing has completed without the need to switch the camera AF switch to M. The lens went back to Pentax and was found to be faulty. They replaced it w/ a new unit.

[PENTAXLOVER]

There are five Pentax users in our photo club. Three of us have had a total of SEVEN 16-50's. The other two guys (one girl actually) have given up on this lens completely. I got a good copy on only my second try. I'm worried though that this lens will not last. There is obviously a design/QC flaw.

[1986Chaitanya]

@PENTAXLOVER somehow I like classic M and A series lenses by Pentax they are the best.

[ar4216]

@PENTAXLOVER That is outrageous, especially given the high cost of this lens.

[MrPark1968]

had the same issue man,

these are the serial numbers of the faulty lenses

SN 9018287

SN 9021149

SN 90112xx something

unfortunately Pentax didn't fix my issue and i moved on. Too much frustration with this brand. Exactly as you said... weeks of frustration.

good luck !