Nikon accessories of some sort (look like weird eyepieces?)

[Scarodactyl]

I was recently at an estate sale, and the homeowner had been a big microscope enthusiast and maybe a dealer. I ended up buying four boxes of stuff, including accessories for my alphaphot as well as some other things I'm less certain about. First up is this odd box of... things? I'm sure this is something normal and obvious, but I really don't know much about compound microscopes.
The length is adjustable and the inside is greased.

[Hobbyst46]

They look like phase telescopes - wild guess. But if they are, I think they should be cleaned of the grease.

[wporter]

They look like phase telescopes to me, too. If you substitute one for an eyepiece, and turn the focusing part in and out, do you see it progressively focusing on various parts of the optical train (objective innards, the condenser iris, etc.) ?

If they are, and work pretty well, you may be able to unload some on this forum. They are typically overpriced on ebay ($100+).

[Scarodactyl]

They look like phase telescopes to me, too. If you substitute one for an eyepiece, and turn the focusing part in and out, do you see it progressively focusing on various parts of the optical train (objective innards, the condenser iris, etc.) ?

If they are, and work pretty well, you may be able to unload some on this forum. They are typically overpriced on ebay ($100+).

Thanks, that's exactly what they do! I'd be glad to part with most of them too. I'm keeping one phase condenser so I guess I'll keep one of these too to keep my options open, but once I make sure the others are in good shape I'll put them up in the selling section.

Thanks for the tip hobbyist. It did seem a bit odd for a microscope component to have exposed grease like that.

[apochronaut]

Actually, the grease is most likely supposed to be there. Bertrand lenses made in that fashion( Olympus had them too) and measuring eyepieces that need to focus on the reticle can have a helical screw as a focus mechanism. When the upper lens system is pulled back. the damping grease used to both lubricate and clutch the action is exposed.