thanks for all the compliments, people.
I'd like to add a few words about the reverse adapter.
I tried it with the 50mm macro but that particular lens is built very symetrical. So in reverse it only magnifies a little bit more (10-15%).
Yesterday I got back a 50mm/1.4 standard/prime and tried that one with the reverse adapter. Wow, the effect was overwelming. Magnification was almost too much.
Dof is nearly non existend, a fraction of a millimeter front and aft.
Even with the extube fixed to the backend to control the aperture the dof was still not much more than 5mm. The 50mm/1.4 is also a bit soft image wise to be of any use as macro with the reversering. A 24 or 35mm might give better results.
One other side effect with a reverse ring is that you lose the ability to fine focus. The focus becomes fixed. Any adjustment in focus must be done either shifting the subject or the camera.