In article <4d4i7n$le3@rebecca.albany.edu>, dr8192@CNSVAX.ALBANY.EDU says (most, about the Nikon lens clip at f5.6, deleted)

> I take them off. I have one pre-AI camera and I use
> the meter in the "uncoupled" or "working aperture"
> mode by pressing the DoF prevu while aligning the
> match needle meter. This bypasses the notorious
> resistor ring which, when worn, is terminal and is
> the death of the meter - no replacement parts to be
> found. My meter is a bit less convenient, but it
> will last until the cell dies, which is a lot longer
> than if I used the resistor ring to do coupled [AKA
> wide-open] metering. (...)

The old-time stop-down method of metering can also be done with
the AI-type bodies with the flip-up AI tab (FE, FM, F3, F4).
One advantage of this type of metering (assuming good blocking
of stray light entering the camera eyepiece) is more accurate
exposure, since the meter reading is being taken through the
actual taking aperture (which may not agree exactly with either
the marked aperture, or its representative, the variable resistor,
especially at small stops).
Hope This Helps