I have to say that the MP-E lens is a blast to use. When I got it home, I put it on a tabletop tripod and putzed around with photographing items on my desk, mostly at 1.5 to 2x, with a variety of lighting techniques and colored reflectors and background. I had great fun taking abstract photos of a metal mini-slinky toy, a metallic charm on one of my flash-drives, etc. I can't believe that people hand-hold this lens and get sharp shots at 2x or greater. Medical specimen photography at 4x magnification was more challenging - focus stacking might be required to fully capture some textures. I can see that my next DIY project will be making a cheap mini-stage to adjust specimen plane to parallel camera sensor plane. It's easier to adjust specimen plane at lower magnification with bits of damp paper towel, etc, but for 4x, I ended up shoving single 2mm squares of towel under one edge of the specimen - pain in butt if you want to have towel out of sight. (Dental wax is fantabulous but is hard to remove from lucite copystand stage).