Noise when changing aperture on my Tamron 17-70mm?

Photoswithreg wrote:

I recently purchased a Fuji X-H2 and a Tamron 17-70mm lens and I noticed that when I change aperture’s via the X-H2 the lens makes a mechanical noise. It’s not super loud or anything but I wondered if that’s normal or not?

The 17-70 has a chatty aperture gear, it's normal.

You don't hear it when changing the aperture via the command dial, as the aperture change usually doesn't apply right away until you half-press the shutter button.

But if you point the camera between dark and bright scenes, the aperture will change accordingly and the gear clicking noise can be heard. My brain completely ignores the noise after 2-3 weeks shooting with it.

From what I observed, if the camera knows which aperture it needs to change to, the lens can do it quickly without noise, e.g. when half-pressing the shutter button. But if the camera is adjusting to the scene, e.g. pointing from dark to bright scene or releasing the shutter button, it sends repeated commands to the lens to close/open the aperture one step at a time, that's when the noise is most audible as it's a long chain of slow clicks.

Given how the lens takes twice as long to start up (comparing to Fuji lenses) on my X-T2, I assume it's a communication issue between the lens and body. Perhaps Fuji didn't release the protocol completely, or Tamron didn't do a good job on understanding it. Thus, the body cannot adjust the aperture as effectively as it should (it waits for the lens to tell it that's the aperture has changed to measure the light before trying again). Perhaps communication is also the cause of lens correction metadata not being embedded correctly in EXIF (as we've seen the issue reported by fernandojval)