They will cover in the macro range, and of course those focal lengths won't focus to infinity on a 6x6 SLR. I've experimented a bit with enlarging lenses on MF, and you just have to test the lenses you have. Some work better reversed, but some are about the same in either orientation. I have a custom Canon FD adapter for my Bronica S2a, and I have an LTM-FD adapter and reversing ring. For macro, I think my Tamron SP 90/2.5 is sharper than the enlarging lenses I've tried on the Bronica (and it covers in the macro range), but I haven't tried my 90mm Apo-Rodagon, which might be sharper. I have a 25mm Luminar and a Canon FD 35/2.8 Macrophoto (also a RMS mount lens), and I think the Canon is contrastier and sharper, and it usually sells for less than a Luminar.