Received a Sigma 105mm F2.8 DG Macro lens for my D90 a couple of weeks ago. Was reading lens instructions last night and found that I get an error message on the camera when i follow the lens instructions regarding setting the exposure mode.
"When you use the Program exposure or Shutter speed priority auto moede, the Diaphragm contol ring must be set to the smallest Fstop. All Nikon AF/MF lenses have a safety button which should be moved to the lock position. When you use the Aperture priority auto mode or manual exposure mode, unlock the button and set the diaphragm value by turning the ring"
In shutter priority and program exposure modes, the F stop is locked at 32 and all works fine. When I unlock the lens and change the diaphrahm value to a larger aperture [smaller number], i get an error message flashing on camera 'Fee' where the aperture number normally is. Troubleshooting D90 manual states that:
Problem: Lens aperture ring is not set to minimum aperture
Solution: Set ring to minimum aperture.
Can someone explain what the diaphragm value on my new lens is and is my D90 behaving correctly. Note that once I set the diaphragm value back to 32, the error message disappears.
thanks in advance