well maybe not 100x, but at high zoom, its usable but there is white fog. oil is not really practical in this situation. I figured its just a consequence of such high zoom. It stops being 'nice' at like 40x.
Say looking down from the top on a BNC connector center pin hanging in a arm off the side of a table (held in small helper hand), for microscopes on big articulating arm/rails (heavy, big and hard to adjust... you gently tap them to get the image centered after the screws are tightened lol)
actually better way to describe it might be a off blue/yellow haze, not white fog, and they are always stereo (for electronics)