Chromatische Vegrösserungsdifferenz? Why on one side only?

[Michael Cytrynowicz]

Thank you Enzo.

With the firt (bad?) condenser I tried aligning it as much as I could, using the 3 screws, but could never get rid of the CVD. Aligning the new condensers worked very easily. Could it be a defective (or abused?) condenser?

A small note: image #3 shows a bit of pincushion.

Warm regards,

Mike aus Oporto

[3nzo]

Hi Mike,
It could be a bad condenser. As for pincushion, I'm no expert, but I think it depends on the lens.
Best regards.

Enzo

[Stephan Hiller]

Hi Mike,

alignment of the objective turret is normally done by a special tool called "Ringlineal" in German:





This tool is screwed into the objective turret instead of an objective with the table fully lowerd. Then the "Ringlineal" is mooved into observation position and the allen screw fixing the turret is slightly lowerd (as you did) and the table is lifted until the rim of the Ringlineal is touching the table without forming a visible gap beween its lower rim and and the object table. In this position the turret is fixed with the allen screw again. This ensures a perpendicurar orientation of the turret to the table and by this parallel to the optical beam path.

Regards

Stephan

[3nzo]

Hi Stephan,
the microscope column and the travel axis must be parallel to use the Ringlineal. Furthermore, the table must be exactly orthogonal to this axis. With which tool can you control all this?
Thanks and best regards.

Enzo

[Michael Cytrynowicz]

Hi Stephan and Enzo - very interesting to learn what you both are saying, I will keep my eyes and ears open!

Gruess aus Porto,

Mike

P.S. Germany 90th minute. Wow!

[Stephan Hiller]

Hi Enzo,

you are absolutely right. The usage of a Ringlineal requires the table to be orthogonal to the light path and the travel axis of the table to be strictly parallel with the light path. With a solid old microscope (e.g. Leitz or Zeiss) not damaged by a drop from a larger height, with all movements still smoothly working, this is normally given by its construction. I never had a problem with this in any of my Leitz or Zeiss microscope stands I have, even after a complete disassembly of the stand (table and drives). The claening and re-lubrication of an objective turret, however, often requires the disassembly of the turret from the stand. Remounting the refurbished turret is easily done by the help of a Ringlineal especially when the turret is not pinned with the column.
Exchanging a fix turret with a dovetail mounted turret on a Zeiss GFL, Standard or Junior microscope is also a typical case for using a Ringlineal for realigning the turret correctly.
Mike had loosen the screw which fixed the turret in the correct position. Realigning the turret then should be done by a Ringlineal.

Regards
Stephan

[Michael Cytrynowicz]

Dear Stephan, I am completely convinced :-)

I believe I am still slightly misaligned - the light path is a bit North of center, so yes, I should follow the procedure you mention. Now the question is, where do I get a Ringlineal?

And, now that you did mention, the thought of exchanging my 5-fach turret for a 7-fach dovetail one DID cross my mind, if I can align it with the Ringlineal :-)

Friendly regards from Porto,

Mike

[3nzo]

Hi Stephan,
other microscopes, such as my Zeiss Jena Amplival, have interchangeable objective turret, turret arm and table. This poses alignment and orthogonality issues due to the dovetail of the turret and table attachment.
With interchangeable lens turrets, an alignment with the Ringlineal may not be resolved if you act on the fixed part because the turrets may have a different misalignment.
Finally, other microscopes such as the larger Lomo ones (e.g. MBB-1A) have the focusing stroke on rollers and parallelism is obtained by acting on threaded blocks.
However, the Ringlineal remains an indispensable tool for understanding the state of the microscope. Where could it be found?
Thanks and best regards.

Enzo