The handbooks that came with the camera itemized caveats for each lens type used close up.

Only the macro was perfect if you floated the ring ok

The 127 might just vignette with both tubes the others worse

the 65 and 55 needed f/16 or smaller and only short tube

Etc.

too difficult to remember think mamiya have ecopys on their site the soft focus is bad enough...

I resisted the temptation to buy either tube.