The title really says it all.

I'm trying to copy some slides using a bellows unit (Nikon PB4) and a 55 Micro-Nikkor. I also have the PK13 extension.

I've used this setup successfully in the past (minus the PK13) to copy slides 1:1 onto print film.

My problem now is that I am trying to use a newer body (old body needs repair), and to mount the newer body the extension tube is needed to clear the rear standard of the bellows. I can get greater than life size, but I can't figure out how to get closer to a 1:1 - I don't want to have to crop almost half the slide to copy it.

What am I missing/doing wrong?

FWIW - I am trying to copy them using a D-type camera, but the problem would be the same if using any of the newer film bodies (ie F5).

I do have a fair number of slides I'd like to copy in this fashion, so it would be great to be able to just set it up and go. Failing that, I may be reduced to taping the slides to a window to shoot them.