Anything is possible given enough time and money! The problem is any such adaptor would cost more than the price difference between a D3000 and a D90 as the demand for such a devise would be very low. It would also have to incorporate optical elements to correct for the additional distance between the camera body and the back of the lens. Similar to a TC. The TC-14E II sells for $350.00(gray) to $420.00(USA) without a motor or any mechanical linkage for "Screwdriver AF". Good Luck and Enjoy your Nikons!