Interesting effect. There is very little depth of field at these mags. Even stopped down to f22. You need bright lights, tripod and long exposures.
I have recently bought a lens for the opposite effect- a fisheye 30mm(for medium format). I tried a photo of a dafodil at about 20cm distance that only takes up the middle third of the frame. I will post them when they are developed-(yes, stil using film

)