Mr. Lambrecht,
Thanks for your reply and advice! It should really be the best solution to conduct the test with my own camera and equipment.
I am totally confused with all that stuff on bellows, extension tubes and magnification.
For my Bronica i have the 80mm (Minimum Focus Distance: 0.8m) and the 150mm (Minimum Focus Distance: 1.5 meters) lens.
There are two extension tubes available for my camera: Automatic Extension Tube S-18 (i guess 18mm) and Automatic Extension Tube S-36 (i guess 36mm) and a 1.4x and 2x Teleconverter.
I can't figure out what makes it possible for me to take a close up copy of the 4x5 inch (or 6x6cm)stouffer tablet.