This photo was done with a Self-made macro lense:
I used the Minolta 35-70/4 with a connection ring (this has a winding for filters on both sides). This ring connected an old Helios 44-2 2/58 in retro position so it worked like a magnifying lense.
Sorry for the place the fly is sitting on, the only chance to come as close as 5cm was on a big pile of doggy sh...

No Digital Darkroom Secret for this, it came out of the cam just as you see it... did only a little cropping