[obican]

Not on my lens, obican. I tried.

 

If you know better, I'd be happy to know which menu setting needs to be changed.

 

edit: just checked a third time, with the 18-55/2.8-4 (which has the same concept as the 100-400 in terms of aperture ring). If I set 

• Aperture to A
  
• Shutter dial on top to A
  
• use a low ISO number
  
• and change in the menu the rear dial with the front dial function
  

Then - and only then - the aperture changes because the camera is now in program automatic and the aperture is depending on shutter speed - which I can select by the front dial. So the aperture only follows the shutter speed - I could not change the aperture independently! But program automatic and value shift is not what I'm looking for.

 

As I said, if you know a secret way, please feel free to share.

 

You have an X-T2 right? I'll drop by to the Fuji store tomorrow and try to remember how to do that. Pretty sure that was possible with X-T1.

 

 

Edit: I think I was thinking of changing the shutter speed via dials and not the aperture. Might be my bad.

 

Edit 2: Nope the manual says you should be able to use front dial to adjust the aperture. Page 274 (294 on the pdf). Might be something to do with another setting. Check if the menu item APERTURE SETTING is set to AUTO+MANUAL.