Auto diaphragm problem

Hi

I have an A-series zoom that has suddenly developed a problem with my LX. When I mount the lens, the diaphragm doesn't automatically open. In fact, it stops down and opens up as you turn the aperture ring as if there was no auto diaphragm control. Then, if I press the DOF preview switch, it opens up and works fine from then on.

The strange thing is, this lens works fine with my ME Super. And all other lenses work fine with the LX. It seems to be a problem with just this combination.

One other thing - this is my only A-series lens, so I don't know if this is significant or unusual, but after taking the lens off, when I turn the aperture ring, the little A-setting button moves up and down (or in and out, if you like) a few times, before eventually popping up to its maximum and staying there.

Anyone have any ideas about what's going on here?

Thanks

Peter

the stop down actuator on K mount lenses (thats the big sticky out one) can become slightly bent so that it doesn't engage properly. Compare it carefully with another lens to see if this has happened. It doesn't take much to mess up the alignment, especially since it seems yours is very close to right.

might well not be the problem, but worth a look as it's an easy fix.

That was it. The tiniest bit of leaning on with a screwdriver (didn't even notice it move) and the problem is fixed. Thanks!