How to: Aperture Control in Inverted G (Nikon Mount) Lenses
Aperture Control in Inverted G (Nikon Mount) Lenses (also works with D lenses).
It's enough to turn the rear cap to open/close the aperture.
It's a bit tricky to place the plastic cylinder in the right place, I checked it several times before making the hole in the cap. The cylinder has to be fixed in the right position in order that when the rear cap is entirely closed the diaphragm is full opened, it has also to be fixed at the right height.
It's not a precise way to control the aperture but I find this solution better than using a piece of plastic temporary inserted in the aperture lever hole.