Use ground glass back to focus for rollback shots?
I am wondering about how best to obtain close focus when using a roll back. I had thought that one could use a ground glass back to prepare to focus with a film roll back, but the ground glass focal plane would most likely differ from that of a roll back. Is this right?
For example on a Patent Etui 6.5x9, would it make sense to use the ground glass to set the focus for a rolex roll back shot? If this does not work, then is there another way to take shots close up and in the macro direction? Or is this not possible?