Need help with Sigma aperture lock!

[vaqko]

I have a Nikon D40 and I recently received a a Sigma 105mm macro lens.
It has an aperture ring, but I can't take any pictures with my camera if I move it, it says "Lock lens aperture ring at minimum aperture (largest f/-number)"

Is there nothing I can do? I just don't understand why it even has a ring if I can't use any other apertures.
I've tried reading the manual, but I couldn't find any help there, so I was hoping someone here could help me!

Sabine

[IABoomer]

Chances are, the lens has a little metal lever close to the optic on the mounting side. This allows the camera to adjust the aperture of the lens according to the meter, or aperture settings you select using the thumb wheel. If you had a much older lens that didn't communicate with the camera, then you'd have to use the aperture ring to set the lens aperture.

You should still be able to pick whatever aperture you want, just use the camera controls to do it instead of the ring on the lens.

[vaqko]

Thank you very much!