A very extended extension tube, what will hapen?`

[All Ex]

Recently I `ve got a rather creasy idea, I`ve found an extended carton roll and I shaped It, with the proper adaptors to an extension tube. I wonder what 1f, instead of f=200, as my objectives require, make my distance from the sensor, with my tube together 755 mm.
I know that the first problem that I`ll face is the illumination, I`m planning to use 3 flashes in full power. The first thing to do is to measure the magnification with my objectives especially wi1h my recently ?btained Mitutoyo 5X 0.14 M Plan Apo.
What do you thi0ng about my experiment?
(For the time being, I`m prerair0ing my rig, If my experiment succeeds I `ll post the results.)