Zeiss Objective Markings

[Grahame]

Hi folks,
Does anyone know of a list of the Zeiss specific marking on their objectives ?
Google has failed me on this.
Currently I'm looking at a Zeiss Jena GF-Planachromat 40/0.65, Phv 160/0.17-C
I have no idea what the GF means, though I see many for sale on Ebay in different forms.
Also the C at the end.
I understand the rest.
Some sort of list would make wading through listings a lot easier.
Cheers
Grahame

[PeteM]

I believe the GF refers to a relatively wide field and the Phv to a phase contrast type; likely with two phase rings. The examples I have have 25mm threads, a 55mm parfocal length on the 100x, good resolution, and not as good contrast as more modern lenses. No idea what the -C means, unless it refers to a cover slip.

[Grahame]

Thanks Pete

[75RR]

You might find this catalogue of use:

https://www.dropbox.com/s/gtjssf4k9c4ni ... 2.pdf?dl=0

Note: No need to create an account to download from Dropbox.
Just scroll to the bottom of the invitation window and click on 'No thanks, continue to view'
Then press 'download' at top right of screen.

[Grahame]

Thanks 75RR,
That was a nice old catalogue to read.
I have a good knowledge of camera and astro optics but these microscope objectives are a whole new ball game.
I'll get there.

[Hobbyst46]

Thanks 75RR for the link.
The PhV is I think a type of phase contrast objective. Perhaps Zeiss Jena did not yet produce P.C. objectives at 1935...since the method was only emerging at that time.

Two interesting history-related points IMO in the Jena catalogue:

1. They list a 74x1.60 objective, monobromonaphthalene immersion, for use without coverslip. This chemical has a refractive index of 1.65. Such objective would not be used at home today... the price of the objective BTW was 3.5 times the best and most expensive apochromatic objective on their list...

2.There are prices in the catalogue;prices do not include packing, and the rate of the currency is 1/2790 Kg of fine gold; goods are picked up at Jena and shipped under the buyers responsibility...

[PeteM]

. . . The PhV is I think a type of phase contrast objective. . .

The Zeiss Jena Phv objectives, at least the set I have, are phase contrast with an unusual arrangement of two phase rings in the objective and two in the matching annulus. The idea is that you have a choice of contrast options; by either opening up the condenser iris to expose the largest one, or closing it a bit to expose just the smallest ring.

My set are infinity lenses. Both finite and infinite versions were made.