A small comparison between two Zeiss turret phase contrast condensers
Posted: Thu Oct 03, 2019 4:38 pm
Hi all,
I have been using the following condenser for a long time:
Achromatic-aplanatic brightfield-darkfield phase-contrast condenser V Z 1.4 (465277)
Yesterday a friend gifted me the following:
Phase-contrast condenser II Z with swing-out lens swinging out 0.9 (465270)
That apparently had been lying unused for many years. The iris aperture was frozen and the top flat glass cover was broken (I was gifted with a spare glass plate, though). This plate is held in place by means of a ring affixed with three tiny screws.
Repair was easy: replacement of the top glass plate; repeated rinsing of the iris aperture leaves with petrol-ether, then drying; cleaning the axle of rotation of the phase-contrast centration levers. A couple of hours later, the phase contrast condenser is alive and kicking.
It is not achromat, so when I close down the field aperture when setting Kohler, color fringe patterns are obvious. However, I would like to see what happens in actual use. It has phases Ph1, Ph2, Ph3. I do not have a 10X Ph1 objective; and, the condenser being of NA 0.9, I did not try objectives of NA>1 yet. My favorite phase contrast objective is the 40X0.75 Neofluar Ph2 (dry).
So here is a small comparison between the two condensers: achromat aplanat 1.4 condenser (abbreviated as 1.4 in the image titles) and the humble 0.9 condenser. All Ph2 setting with the 40X0.75. Single images, resize only.
BTW, both condensers have empty ports; I have tried in the past to occupy them with home-made Rheinberg filters, but finding the right size and centration proved to be time consuming.
Comments are welcome.
I have been using the following condenser for a long time:
Achromatic-aplanatic brightfield-darkfield phase-contrast condenser V Z 1.4 (465277)
Yesterday a friend gifted me the following:
Phase-contrast condenser II Z with swing-out lens swinging out 0.9 (465270)
That apparently had been lying unused for many years. The iris aperture was frozen and the top flat glass cover was broken (I was gifted with a spare glass plate, though). This plate is held in place by means of a ring affixed with three tiny screws.
Repair was easy: replacement of the top glass plate; repeated rinsing of the iris aperture leaves with petrol-ether, then drying; cleaning the axle of rotation of the phase-contrast centration levers. A couple of hours later, the phase contrast condenser is alive and kicking.
It is not achromat, so when I close down the field aperture when setting Kohler, color fringe patterns are obvious. However, I would like to see what happens in actual use. It has phases Ph1, Ph2, Ph3. I do not have a 10X Ph1 objective; and, the condenser being of NA 0.9, I did not try objectives of NA>1 yet. My favorite phase contrast objective is the 40X0.75 Neofluar Ph2 (dry).
So here is a small comparison between the two condensers: achromat aplanat 1.4 condenser (abbreviated as 1.4 in the image titles) and the humble 0.9 condenser. All Ph2 setting with the 40X0.75. Single images, resize only.
BTW, both condensers have empty ports; I have tried in the past to occupy them with home-made Rheinberg filters, but finding the right size and centration proved to be time consuming.
Comments are welcome.