October 15, 2019

My Zeiss Phase Contrast Microscope

This is a beauty. I picked it up for a few dollars at an auction where nobody else recognized what it was. It is a black enamel microscope, and clearly a first class item in its day, and perhaps even still. I am still working to figure out what model it is and to find a manual for it. Some indications are that it may be a "Zeiss Standard WL". It is black enamel -- on brass I am told! In the Black Zeiss Standards there was the Junior, GFL and WL.

Description

eyepieces  Kpl 8x

Objectives are marked:

Plan 2,5/0.08  160/-
10/0.25  160/-  Ph1
Neofluar 40/0.75  160/0.17  Ph2
Neofluar 100/1,30 Oel 160/-  Ph3

The Ph1 .. Ph3 markings are in red -- what is this all about?

Then there is the big removable condenser gadget.
It has a variety of adjustments I wouldn't dare monkey with, and the big disk rotates to
settings marked   D  J  1  2  3  4  5 (i.e. 7 positions are possible).

Above the objective turret is a disk that rotates, that is marked: PH  1.0  1.6  2.5  (4 positions).
I learn from a listing for a Standard WL (which it describes as a "Research Microscope" that the plate above the objectives is what they call an "Optovar". The same listing describes the condensor disk as follows.
Optovar: This device fits in between the binocular head and the stand and provides magnification factors of 1.0, 1.25, 1.6 and 2.0. There is also a phase (PH) position which inserts a Bertand lens into the light path for alignment of the phase plates in the phase condenser.
(Mine apparently has only 3 magnification factors, and different, as listed above).

Condenser: The microscope is equipped with an aplanic, NA = 1.4 condenser that includes phase 2 and 3, brightfield (J) and darkfield (D) positions. There are controls for adjusting the iris aperture and the centration of the phase plates.
Mine has Phase 1 through 5, along with D and J.

Resources

My scope is not a Lumipan, but the article is interesting.

Condensor disk

Illuminator

The bulb is marked 6V, 15 Watt and was made by Phillips Belgium. I did not receive the transformer as part of my purchase, but presumably this requires 6 volts AC (and a dimmer would be a fine part of the setup). My bulb, though ancient, seems intact. It mounts with a curious 3 prong bayonet base.

Have any comments? Questions? Drop me a line!

Tom's microscope pages / tom@mmto.org