Originally posted by Ash Av mode on camera will not permit the lens to stop down according to the aperture setting on the lens's aperture ring. It will always shoot wide open. (That's the 'crippled' KAF2 for you...)
True, the user still needs to turn the aperture ring manually. I didn't mean to confuse.
I find the position of the green button a bit odd. I prefer the DOF-Preview lever instead. Yet, sometimes it's easier for me to start off metering wide open in this crippled AV mode, and adjust EV-comp with the front wheel, which will adjust the previously metered shutter speed accordingly, while I manually close down the aperture ring -- turn the aperture ring one click (1/2 stop), turn the front wheel one click (1/2 EV) ..
I barely go past f8 with this lens, so I'm not hopping all over the place with EV comp. It'd be different story if the range was from f1.4 and up.