So would the #116 feature request, if implemented, result in the instance of a chipped non-AiS lens, in accurate exposures at the actual aperture set on the lens and notified to the Z body by the photographer via the appropriate menu screen? Is this what is envisaged?
Chipped non-AiS lenses can never be stopped down correctly, due to the non-linear aperture mechanism. An example: Using the CPU communication and setting the lens to f/11 (either by moving the aperture ring, or dialling in the number from the camera's side), for example, will make the camera calculate the correct exposure for that f-number. However, when the actual exposure happens, the lens is ordered to stop down to the position corresponding to f/11
on a linear scale. For a non-AiS lens, that means there will be over- or undershoot of the final aperture with the end points of the aperture scale only being correct.
In most cases, the deviation is +-1 stop or less, so the latitude of the digital system can assist in the later post processing. A few lenses will show greater variability and one should from experience be able to use manual exposure and a correction to handle these situations.
To reiterate:
the exposure is set correctly, but the non-AiS lenses don't work as expected under a linear aperture model. Thus under- or overexposure will result.
For an AiS lens, setting the aperture on the lens in fact will produce a more even and consistent exposure. Stop-film makers tell me this advice actually helps a lot when they work under fixed light settings in a studio.
The underlying reason why I'm pushing the suggested #116 option is that the camera will handle much better if not all controlling actions are on the right hand. One can use the left hand to support the lens and concomitantly set the aperture, which leads to a much better grip and stability. Nikon Df handled easily in that manner and I do wish the same with the Zf.
