With regards to the aperture, unfortunately that won't work. The aperture ring is closed by a small little lever by the camera itself. Once the lens is removed, it closes right down to the smallest setting. A manual lens is difficult as well. Without the lens being mounted to the camera body, the lens stays fully stopped down. You can hold the lever on a manual lens to the preset f-stop though, or, again, Nikon makes an adapter ring that has a stop down lever. You set the aperture, move the lever to fully open the lens so you can focus and meter, and then when you are ready to take the picture, you move the lever and it stops down the lens to the preset setting. Not sure, but Canon must make something similar to this. The Nikon adapters are the BR-4 or BR-6. Pics are in the beginning of the thread