[liukaitc]

well, there is still a bit air blow out from lens body when mounted on camera
well, I think as people mentioned above, it should be fine.

[chesebert]

ok, I just got my 16-50 repaired for SDM issue.
but one issue I had before was that when I zoom in and out, there is air blowing out.
I do not experience this kind issue with my other lens (for example 50-135 and kit lens)
but after it got repaired, I find this issue still exist.
so..........

Guessing it appears to be a defective or loose seal.

[Mareket]

If it was a loose seal surely the air would escape from the lens too, and the blow back from the SD card slot wouldn't be so strong? Sounds like the seals are working just fine to me. I was out in a rainstorm the other day with my 16-50, and that does the same air blowing thing, with no humidity inside afterwards.

[chesebert]

If it was a loose seal surely the air would escape from the lens too, and the blow back from the SD card slot wouldn't be so strong? Sounds like the seals are working just fine to me. I was out in a rainstorm the other day with my 16-50, and that does the same air blowing thing, with no humidity inside afterwards.

Right, apparently I didn't read the follow-up post before posting.

[liukaitc]

It does blow out from lens body too
the air blow out from the lining around the lens body
you can hear the sound come out when I zoom in and out
I do not think that is normal..
how about your guys lens??

and just check the repair service they did
clean and repair sand/grit type substance
I never abuse my lens and I did not even bring it under harsh condition weather.
how come there is sand inside. is that possible due to loose weather seal??

[Mareket]

I can sort of feel some air movement around there when I zoom. Not something I'd notice though, otherwise I'd have said something already. And I do abuse this lens somewhat, it's been out in the rain a lot (thanks to the wonderful North East coast of England), and at worst I use it after climbing down a muddy hill bank now and then, covering it in mud. That stiffens the zoom and focus somewhat, but that worked itself out after a few days and it's fine now. A quick rinse under the tap sorted it out methinks.

If it's something very noticeable then a second opinion is needed really, it sounds sort of odd to me, but then I don't know what the extent is. The 16-50 will blow air around a lot more than the 50-135 though, as the elements seem to move around much more with many more moving parts in the former, whereas the latter has a fixed rear element and internal zoom as well as focus, so it is a pretty solid unit.

[liukaitc]

okay...
anyway I do not have option now.
at least the SDM works fine now, so I can use the lens now.
after switch to kit lens for 6 weeks, I really think 16-50 is a lot superb. now I do not want to go back to kit lens anymore...