My question is pretty straightforward: this lens' aperture stopped working for some reason. What could it be the cause?
Me and a friend of mine tried it in studio, attached to a D750, and when we selected f2.8, it didn't make any difference to f22.
We tried other lenses and they all worked fine, and before you ask, yes we were shooting totally manual (time-priority or program modes).
1 month ago the lens worked perfectly fine on my D610 and the lens has never had problems of fungus, misuse, or whatsoever.