So, this blog (credit to mattdm for pointing it out) says:
Firstly, when you turn the lens around you obviously lose the CPU connection between the lens and the camera, so say goodbye to autofocus, metering (in most cases) and aperture control (though I’ll come back to that)
Then:
The advantage of this old lens is that it has a manual aperture ring, which neatly neutralises the loss of automatic control mentioned above.
So, since G lenses don't have an aperture ring, aperture can't be controlled anyhow if we reverse the lens?
Secondly, is it practical that we set the metering and the aperture (manually) before taking the lens out and reversing it?
Is there any other way to get around this problem in G lenses (assuming that the camera bodies have the manual focus, aperture, metering controls)?