From the time it was difficult to do macro, using extension tubes, reversed lenses, conversion tables and very, very dark viewfinders... only to find out after developments that exposure was wrong anyway.

O.K. to be honest, you did not need this setup to photograph a rose, with this extension you could take an area of 6x10 mm in full frame, DOF approx. 1 mm. or with little more extension a head of a fly at full frame, if you still could get light on it.