Originally posted by stevebrot for 35mm film to APS-C, we actually want 1:1.5 meaning an extension of 33mm with a 50mm lens
The
Pentax K Auto Tube set
Will get you to 32mm, with tubes 1+2. Other brand tube sets will likely get you in the range too.
You will need a lens you can directly control aperture with; an A or older.
Still need a rig to keep the slide or neg a constant distance and square to the end of your lens. That tends to be the tricky part, if you're not square you can't get focus across the film.
Perhaps something like this?
amazon.com : Nikon ES-1 52mm Slide Copy Adapter : Camera Lens Adapters : Camera & Photo?tag=pentaxforums-20&
I have the Pentax tube set, can vouch for them, no experience with the Nikon gadget though,
Let us know what you come up with, I keep seeing this come up, and don't think I've seen a good solution,
Lord knows I have the same problem, just not motivated to deal with it yet.