Metering with g-mount adapter ring?

Any cinematographer ninjas out there using a light meter and Nikon G adapter on MFT?

How do you determine the aperture when it's controlled by the no-click ring on the adapter? Do you buy one adapter for each lens and calibrate them by hand? Any tricks and tips?

Thanks in advance.

In this case we don't use a light meter and we just rely on the built in zebras.

The new Metabones adaptors have a much more accurate aperture control system. I've yet to test mine against a light meter but should be closer than any other G adaptor due to the way it's designed (it has a cam the emulates the built in lever in Nikon bodies).