Help with more info about an old lens

[Pas]

Hello to all,

I am new here and I would like your help - recently I bought two old lenses and I found lots of information about one but not about other - i found some general info but not fot this exact lens - "Monar" F: 3,5 / G.Rodenstock Munchen - it is about 5 inches long (12,5 cm) and filter size is about 3 inch (7,5cm) - pictures attached - I found some similar lenses but not this exact one so if you have more info about model, year...etc. I would be grateful.

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Also other one is Dallmeyer 3B - found lots of info about it but I was going trough this forum and saw sometimes there are fakes - what is best way to check is it a real thing?

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P.S. - when I bought them they were dusty and dirty so I cleaned them with water, baking soda and lemon juice mix and oil them lighly with olive oil (found on net that is good for cleaning brass) - was that ok to do? - took me 2 days of rubbing with cloth but now they look much much better :)

Thank you!

[goamules]

The Dallmeyer is real, it's not fake. The engraving all looks fine, and no one really faked them that often. However, it looks like you scratched the brass quite a bit polishing it. With a high quality, desirable lens, in most cases, it's best not to try to polish them, just leave them as is. But sometimes they are very rough, with partial varnish, partial verdigris, and they do look pretty bad that way. In those rare cases, you need to polish a lot less aggressively, using something like silver polish.

[Pas]

Thanks Garret, that is good news :) I tried to be as gentle as I can, that is why I used cloth and rubbing by hand - didn't want to use polishing paste or similar I just wanted to remove dirt and there was some scratches and small dents on them already...

[Steven Tribe]

If you have to clean (a second attempt, perhaps?) ALWAYS keep the cloth in one place and rotate the barrel! Sractches that are parallel with the ends of the barrel are almost invisible. Random movements create the appearance you have now.
As far as I remember, the Monar is a very rare soft lens from München which never achieved great sales. You (we) might find out by using the search function here.

[Art Smith]

The very best and quickest polish for tarnished Brass is readily available in your kitchen or grocery store, BEFORE using it on anything Camera oriented clean that old brass hose nozzle. it is, Worcestershire sauce. Put it on a cloth spread it around, wait a little, wipe and rinse rub it to the degree of polish you want. if it works to well thin it with water, to what ever degree that suits you. ART?

[goamules]

It's the vinegar, acetic acid. Citric acid works too. So anything made with those, including catsup, will take away tarnish. The problem with brass is, it will also leach out the copper onto the top surface, if left long enough, making your brass lens look an unoriginal copper. I don't recommend any acid, or even polishing any but the most crusty lenses. If the lens is rare or desirable, or has 50% of the original varnish or more, leave them alone.

[Pas]

Thanks for advices, well original varnish was gone and it was almost black with some parts that looked like pine resin smudges - sticky dust and dirt... inside and glass were dusty but ok, but outside brass looked horrible and sticky (and it didn't move) so probably I rubbed harder than I should sometimes... I am thinking of another go as Steven wrote with rotating barrel so if I get lines they will be parallel with ends.