I have a used Nikon D90 with a 10 or so year old 52mm Sigma auto focus lens. I just acquired the camera and I am trying to take pictures with it but whenever the center of the image becomes far away, the camera will not take the image. I can hear the motor in the lens trying to turn the focusing dial but its not moving. I just don't get it because I see the image in the viewfinder and I'm saying "take" but it just makes a little noise and doesn't do anything. I've tried it on the P, S, A, and M settings, which I don't think should matter.
Thank You
Added (1). I have been looking at the manual, in case you were wondering.
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