Unidentified Zeiss epi objective

[TiggerScope]

Hi all, can anyone identify this unusual (to me) Zeiss pol epi objective? I know it's epi from the "Aufl" on the barrel = auflicht = epi, and red lettering with Zeiss = pol.

This one is a 100x/1.30, but I've also seen a (presumably earlier) 100x/1.25 version.

In the same series are 40x/0.85 oil and 16x/0.32 and possibly others.

The bayonet adapter tells me it's for the IIC epi single nosepiece.

I can't find any reference to them in my lit. I'm wondering what they were used for that the usual Epiplan pols (that we use for DIC) couldn't do, how the image quality is etc.

Thanks
Peter

Auflicht 100x 1.25.jpg (70.47 KiB) Viewed 638 times

[apochronaut]

I don't know this particular objective but most companies mfg. shorty objectives like this vertically illuminated one for use on some stands that were modified with a combination vertical illuminator/nosepiece, that threaded into the port in the bottom of the optical tube.
Standard biological objectives in the day had an optical section of less than a cm. depth at the bottom of the objective barrel followed by a diaphragm section that made up the rest of the parfocal length. Because the vertical illuminator had considerable depth it was included in the parfocal length, thus the objective body contained only the short lower optical section.
In a case such as this one which is an oil objective, it likely will work with or without cover, so it may be just the optical section of a conventional 100X 1.3 objective in a stubby barrel.

[TiggerScope]

Thanks, you are quite right, this does have a long extension above the optical section in the body. I fear the optical quality won't be up to the standards of the black Epiplan Pols, and especially the "holy trinity" of 16x/0.40, 25x/0.80 and 40x/0.90 Epiplan-Neofluar Pol oil. Wonderful they are but not so easy to find.

I'm still interested (just idle curiosity) in who would have bought the Aufl objectives, and for what purpose. Many of the Epiplan Pols had long extensions too, which normally fitted into INKO prisms but might as well have fitted the centration collar. Maybe if, as you probably correctly suggest, they were just standard non plan achros, they would have been a cheaper option than Epiplan Pols, which were a bit expensive. The 40x/0.85 Aufl is also oil, so I don't know what achro it would have been taken from, and the 16x was dry, but then at 0.35NA it's not going to care if the slide is covered or not.