ADVISE PLEASE

Ah brilliant ! Just put the aperture ring on A as suggested and yes, I can now use the dial to change aperture ! This is especially good for me because the lens is a bit stiff to operate anyway and especially between 8-22 when you have to fiddle with a little release button. There it's really fiddly and sometimes sticks !

ya made my day, thanks.

DERYN

AND, in M mode I set the aperture with the dial, press the green button, and hey presto, it sets the speed !!! BRILLIANT.

DERYN

Way to go Deryn. No stopping you now.

Yes, with M mode, although sometimes it won't really be correct and some manual compensation is required then.

Av mode with these lenses only works with the largest aperture (smallest f number). M mode is required for the smaller apertures (and of course can be used with the largest aperture too if you like).

Not 100% sure on this but I believed that the camera stops down the lens in AV-mode when you press the green button and reads the value and opens the lens again. It meters the value before and when stopped down and aplies the diffrence to what he is metering... I've only used an old lens twice so aint sure but I thought it did it like this, so if you change your aperture you need to take a new metering.
I'm sure someone can test that.

Also when your lens don't stop down but simply reduce the aperture with an higher f/number, AV also works.
The meter meters the light that goes through the lens at f/22, f/2.8 or any other value so that's preciesly what you want.

Stefan

With a K mount lens that has no "A" setting you have to use manual mode and press the green button (AE-L button on some models) to meter. If you use the lens in Av mode you will get correct exposure, BUT only at widest aperture, irrespective of where you have set the aperture ring.

With a M42 mount lens which physically stops down as you turn the aperture ring, you can use Av mode normally.