MicrobeHunter.com Microscopy Forum

May be you can find your objective in one of the brochures that can be found here: http://www.leitz-ortholux.de/links.php
In some tables the free working distance is stated.

Bob

Thanks for the photos and numbers
We can't really justify treating that as a 'thin lens' ... So, without some idea of the optical design, calculation becomes guessing ... but your practical result is not unexpected.

MichaelG.
.
Edit: It may just be coincidence, but it looks like someone has been experimenting with this example:
https://www.ebay.com/itm/Leica-Leitz-3- ... 3015897278

I have just downloaded this useful looking document:
http://microscope.database.free.fr/500_ ... rriers.pdf

Maybe we can find enlightenment there.

MichaelG.
.

Eureka:

As a footnote to this discussion:

This patent gives a good idea of what is involved in designing parfocal low power objectives
https://patents.google.com/patent/US4027951A/en
https://patentimages.storage.googleapis ... 027951.pdf

MichaelG.

MichaelG.,

Looks like it's a mystery solved!

I guess I just need to consult you guys before I start buying things. (at least I didn't pay too much for this I guess)

With so many different types of objectives it's easy for a beginner to make mistakes or get something that isn't exactly what they thought they were getting.

Thanks again for all of the info and effort you guys have put in to figuring this out, looks like I have a lot to learn(already knew that though!)

Have the same lens which came from a Leitz Laborlux II. Unlike any lens that I have used before, the working distance is VERY long - over 3cm. Crank the stage WAY down. Some scopes may not have enough stage travel to use this lens. It is definitely not parfocal with other lenses.