Is that the wheel on the back of the camera, below and to the left of the AE-L button?
Shel > [Original Message] > From: Godfrey DiGiorgi > > DS: > > In Manual exposure mode on the, the thumbwheel wheel controls both > aperture and shutter speed. Turned by itself, set shutter speeds from > 30 seconds to 1/4000 second. Press the "+/- Av" button and the > thumbwheel sets the aperture.
