Episcopic illumination



Two letters of the word “LIBERTY” on an American 25-cent piece, magnified 60x


Two years ago, I wrote a post, with photos, about my Nikon Model S microscope. People who are Googling for this classic microscope often find my post, and it has been quite popular. In 2016, I did not have an “episcopic illuminator” for the microscope. I recently bought one on eBay. These devices for Model S microscopes seem to be fairly rare and don’t come up for sale often — at least not at a decent price.

An episcopic illuminator is a device that lights the specimen from above. What you see in the microscope is light reflected from the specimen. The opposite of this is “diascopic” illumination. In diascopic illumination, the light is below the specimen. What you see in the microscope is light that is transmitted through the specimen.

As you might imagine, both types of illumination are sometimes used together.

Somehow, my Nikon D2X camera seems to have infected me with a fetish for optics. Like my Nikon D2X camera, the Nikon Model S microscopes are now considered largely obsolete by professionals. But collectors and hobbyists snap them up for their quality and their continuing usefulness.

Unfortunately, the through-the-microscope photos here are of poor quality, because they were shot with an iPhone held over the microscope’s eyepiece.



⬆︎ The episcopic illuminator is the attachment on the left with the lettering “Nikon / 69368 / 1.5x.” Similar illuminators are an option on many microscopes.


⬆︎ The lamp below the microscope stage is a diascopic illuminator.


⬆︎ This is a blade of grass, with both episcopic and diascopic illumination, showing the barbs on the edge that can irritate or even cut tender skin.