Brass Lens: to polish or not to polish?

[Cameron Cornell]

Here is a website with information for museum conservators: http://canada.pch.gc.ca/eng/1439925170362

[TomAlf94]

So fast forward some solid seven years and a pandemic in between.

What happened to your lens?

I've been reading this and some other threads just about polishing and lacquering brass lenses. All I got from it was you people have some strong hearts. I might have mine disfunction if the process takes a turn for the rust.

I have a small projection lens, nothing too fancy, not even a maker on it. It is still very special to me and I like to care for it a lot. How do you guys identify lacquered surface from bare brass? I don't see any fingerprints or even browning except from one small spot where I could believe I see a different layer of material (pretty small to be sure). I guess what I'm trying to figure out is if it still has some of the original finish.

I believe a soft cloth would be the best caring-for-this-finish solution(?)

[Cameron Cornell]

I polished that lens and never, ever regretted it. Over time, it developed a beautiful patina, as brass does.

I made the decision based on the fact that it was obvious that it had been polished at some point in its long life because I could see a couple of tiny, tell-tale bits of old, dried polish in the seams.

Furthermore, the idea that you'd leave brass unpolished on a working lens for the sake of keeping it old-timey seems a little bit silly to me. Polishing tarnished brass, especially if the tarnish is uneven and unsightly, seems like proper care and maintenance of a tool. If the lens had some historic significance, say, a lens used by Timothy O'Sullivan, obviously this would not apply.

[ic-racer]

Polish!

This is an old Anthony landscape lens I restored.

[Drew Wiley]

No. I wouldn't polish it, because I'm too lazy. During my historic building restoration days, I've had to polish so much damn brass hardware that the mere thought of it makes me sick. Then a couple decades later I was selling hundreds of thousands of dollars worth of brass door and builders hardware every year, so that the memory of that makes me even sicker, needing to constantly tell people they either had to keep polishing it, or else let it age gracefully. Eventually clear titanium factory vacuum deposition coatings arrived (much like lens coatings), at least on the expensive stuff, and that finally solved the issue. I much prefer oiled bronze. I even have an oiled bronze kickplate on my front door. One of my outdoor cats, in a gesture of territoriality, added the authentic verdis gris ammonia spatter design, which I periodically have to scour off.

[Serge S]

I like the patina of age - makes it original to me - and it's only original once

[Drew Wiley]

Uncoated brass itself can be artificially aged quite fast; but the process wouldn't be good for the lens elements.