I have a Nikon D5100 (which has no AF motor in the body) and a Tamron 90mm SP macro lens. The lens has no AF focus motor either (or at least it doesn't seem to be compatible with the body), and has an aperture ring.
What settings should I use in order to to use the lens correctly? Should the aperture size on the lens always be the same as on the body? Can I use aperture priority, or should I always use manual?