In article , hinkey@pop.seanet.com says...
>I have an Nikon F3 and have 28-70 and 70-210 variable aperture zoom >lenses. How does one meter correctly when the aperture displayed in the >viewfinder is not what it is actually going to be? Do you set the >aperture to say f/8 in the viewfinder, meter the scene, and then change >the aperture ring back to where f/8 is marked on the lens barrel? Or >is it time to get that 28-70 f/2.8 and the 80-200 f/2.8?

The simplest ways are one of the following: In manual, meter normally,
but do it at the focal-length you will use to take the picture, then take the picture (no compensation or changing of aperture is required).
In auto, just go ahead and shoot (the camera takes care of the changing
aperture with zooming by changing the shutter speed to compensate -
UNLESS you have locked the exposure setting and subsequently zoomed).
BTW (I am amazed by the people who do not know this, so it is worth
mentioning:), apertures are infinitely variable - you are not stuck
with whole stops. You can put the aperture ring at ANY location,
such as, f8.1743622, if you could locate that position on the ring!
Hope this helps.