About extension Tubes

Yes, mine are anodised Vivitar ones, and behave in the same way. Actually there are two levers on mine, the aperture coupling lever, which is almost hidden, and the stop-down lever itself.

Paul

mxx wrote:

I've just tested the use of extension tubes on both my K1 and K5, and they work exactly the same way on both cameras. The tubes are manual Vivitar ones with only an aperture lever linkage.

Using them "as is" produces the same results as that of the OP: The aperture of the lens does not close down. The problem in my case is the anodized black finish of the tubes: It prevents the tubes from shorting the electronic contacts on the body, as a normal lens would do. Using an aluminium strip between the tubes and the lens mount to short the contacts results in the aperture closing as it should.

Also: The use of the aperture ring should be selected in the menu, as pointed out by other posters, the camera should be in manual exposure mode ("M"), and the focusing mode should also be Manual (not absolutely sure about the last one, though).

In my case a permanent solution could be to sand off the anodized finish on the part of the tube which makes contact with the electronic contacts on the body; or fix a piece of aluminium foil to that part. Of course, all your tubes (they usually come in sets of three) should be treated that way in order to work with the camera.