It definitely wasn't a reversed lens. It was used in an underwater rig and to my knowledge none of them support reverse mounted lenses. I've never done it, but I have definitely seen people who at least claim to be in those magnification levels without reversing using f-mount lenses.
I found the threads on the diving forum but unfortunately it's too old and the pictures are no longer hosted.
In this first
thread he was shooting using the 105 and a 3x TC. At least one other person on there is shooting with a rig that's in the 5 or 6 to 1 range without using reverse mounts.
In
this thread he talks about stacking a 3x and a 2x on the 105.
I really wish the pictures were still on those threads...they were quite amazing.
In any event, I don't want to sidetrack your thread, people should be ewing and ahing over the images, not a tech discusion
. We can continue the conversation in a dedicated one if you want.
Seeing the clarity of those shots at that magnification, I still think 8 c notes is a really reasonable price for that lens.