Mystery Nikon Magnifier

[MichaelG.]

I have a Nikon item which appears to be one of these:

https://www.ebay.com/p/3037734298

https://www.ebay.com/itm/275027711597

Unfortunately, I have no idea what it is intended to fit
… and strangely, although the lower lens element works as a very nice ‘magnifying glass’ … I haven’t found any setting where the complete device will achieve focus !

An instruction leaflet would be wonderful; but I would settle for identification of what system it belongs to.

Thanks in advance
MichaelG.

[deBult]

I have a similar one, Olympus.
The Olympus onecis used as an alignement tool after a repair exercise involving the optical train.

[MichaelG.]

Thanks for that … I shall investigate further

MichaelG.

[PeteM]

Might also be part of some version of Nikon's 35mm camera apparatus - used to view and achieve accurate focus. Similar, perhaps, to this:
.
.

Nikon film camera & viewer.jpg (111.56 KiB) Viewed 1646 times

[Tom Jones]

I have one of the Olympus ones (U-FT) I use for aligning BH-2s, but I think their original use was as a focusing aid for the film camera modules.

[Macro_Cosmos]

Fine focus assist to be used with a camera mount apparatus that had its own eyepiece, it mounts onto the eyepiece.

[MichaelG.]

.

Thanks for the further replies
… I now need to expand upon my original question

What design of eyepiece, on what instrument ?

As originally stated:

although the lower lens element works as a very nice ‘magnifying glass’ … I haven’t found any setting where the complete device will achieve focus !

… from which I would deduce that it is intended to work in conjunction with other optics, rather than just being a loupe.

MichaelG.

[Macro_Cosmos]

As originally stated:

although the lower lens element works as a very nice ‘magnifying glass’ … I haven’t found any setting where the complete device will achieve focus !

… from which I would deduce that it is intended to work in conjunction with other optics, rather than just being a loupe.

MichaelG.

I had a look at mine. My approach would be to get the top lens off and mount it in a screw housing to allow focusing (3D printed), similar to a centring telescope (CT).
Evident made focusable ones (FT-30), I used it as a CT for a while.

[MichaelG.]

Thanks for that ^^^

MichaelG.