Well it pays to go back over old threads when you have a brain like a sieve.
I have checked out my bellows but the snag is there is no link to the diaphagm and I do not have the necessary bit. That would make life off the tabletop set up a bit tricky. So I put all my auto tubes on and the fov is 10mm. Having resurrected the old 'macro on the cheap' thread I knew something was there as far as fov with reversed lenses, and sure enough, for post #85 I took pics with some reversed lens combos against a steel ruler. Link
http://www.worldphotographyforum.com...?t=1618&page=9
Megga rain tomorrow I hear, so maybe Tuesday I will have a go.
Don