Help me whit objetive leitz SW ?

[Gatotacha]

Cordial greetings.
Help me to identify some leitz objetives that came with an Ortholux that I just bought ,please
What is the meaning of the letters sw
And 45L,
Thanks You

[Gatotacha]

Objetive leitz SW
45:1 L
Na : 0,65

[JB]

Hi,

It's a 45:1 achromat objective with a numeric aperture (NA) of 0.65

"L" could be the old (at the time) objective type. Leitz called it's 45:1 objectives "6L" http://www.science-info.net/docs/leitz/OldLeitzObjectives.pdf

S-W probably doesn't mean salt water but could be the name of the company. If there is no "Leitz" logo, it will be from one of the many smaller companies in Wetzlar at the time. https://www.ebay.de/itm/183749329746 Maybe Siebert Wetzlar?

It's interesting that the writing is upside down!

[smashIt]

It's interesting that the writing is upside down!

maybe it's meant for an inverted microscope?

[Gatotacha]

Thank you very much for your explanation.
If I was tempted to try it with water, but I was not very sure, because I have the objective 10x .with the same inscription and the distance of work I can not immerse it in the preparation, or perhaps if I use it in a petri dish...?
But even so I now believe with certainty that it is what JB explained, that they were smaller manufacturing companies.
Still, if you give me courage to try and one last recommendation, I would try it as a water immersion.
Very happy for your attention and response.

Translated with www.DeepL.com/Translator

[JB]

Hi,

Don't try immersion. These are definitely dry objectives. 

[Gatotacha]

   Okay, I'll follow your instructions.
Thank you .