Here is a darkfiled image of a Water Boatman from a recent pond dip.
It was shot on a Swift M-330D Trinocular with a Swift 5X objective on an Olympus E-420 with an Olympus OM 28mm f3.5 as the relay lens. 92 shots in Zerene Stacker PMAX. Home made darkfield stop.
The specimen was mounted on a well slide in Methyl Cellulose with no cover glass due to its thickness. The swirls are particles moving while shooting the stacking set. I found them kind of appealing so I didn't retouch them out.
Images made through a microscope. All subject types.