Fungus on antique Lens: Can it be fixed?

[Two23]

1. From the advice in several responses here, remediation looks less and less likely.

2. I want to do some additional learning though. I have doubts that this is an 1890s era item. I have read somewhere that the marking from 1860 through 1863 were "Darlot Paris" as engraved on this lens. Previously the marking would have been "Jamin Darlot" and before that, just Jamin. .

1. Try what I said--exposing to direct sunlight for a day or two. If it's fungus that will make a big difference.

2. The Jamin/Darlot period was far earlier than this lens and involved Petzvals. This lens is much later than that. For starters rectilinears weren't much in use until about 1866 and later. This one has later construction so early 1890s is a good guess.


Kent in SD

[Steven Tribe]

Thanks Everyone.

From the advice in several responses here, remediation looks less and less likely.

I want to do some additional learning though. I have doubts that this is an 1890s era item. I have read somewhere that the marking from 1860 through 1863 were "Darlot Paris" as engraved on this lens. Previously the marking would have been "Jamin Darlot" and before that, just Jamin. It might be worth remembering the "Rapid Rectilinear" is a term rendered in English, while "Hemispherique" is a term rendered in French, by a Frenchman. Later marks were different in details of address and so on I think. I am just learning these things, so any information is appreciated. I am open to being educated or schooled.

Perhaps I will spend some lens money on a reference book someday. Wikipedia does not have much on it.

Engraving styles mean Little with Darlot. The same applies to serial Numbers - there are either Numbers/no numbers relating to design or many restarts.

You are misled by the simple extension/locking device which Is the same style as used by the 1865 Universal casket set. American makers also used fancy combinations of names in the late era

[Drew Bedo]

kebt and Steven:

Thanks for your info. I am still learning. A reference book is now on my Christmas wish list.

Stven. . .are you thinking that this could be an American made lens . . .like a Chinese knock-off of a Rolex?

[Tracy Storer]

Set the lens facing direct sunlight for a couple of days. I once opened the shutter and taped the lens to a south facing window.

Kent in SD

Make sure there is nothing flammable in the path of infinity focus (as the sun transits the sky).

[BrianShaw]

Make sure there is nothing flammable in the path of infinity focus (as the sun transits the sky).

This sounds like a posting based on experience!!!!

[LabRat]

This sounds like a posting based on experience!!!!

A magnifying lamp started a fire on my bench at work a few months ago, when early morning bright sunlight hit it and it burned a plastic ventilation tube, which then set fire to a stack of plastic bags nearby... Luckily someone was there then to put out fire, but a real mess from particle remains of fire extinguisher... And not the first time I've seen it happen...

About the lens, the pix with the light passing through does not look too bad to attempt major service... I'd test it first to see how it works as-is...

Steve K

[Darren Kruger]

Make sure there is nothing flammable in the path of infinity focus (as the sun transits the sky).

Even mistakes can become art. See Chris McCaw's Sunburn work. https://www.chrismccaw.com/sunburn

I remember seeing a video of him taking a day shot with one of his home built ULF cameras with smoke coming out everywhere from the camera.

-Darren

[Philippe Grunchec]

http://www.lereveedition.com/fr/doss...4-jamin-darlot

Jean-Loup Princelle's books are very useful!

[Drew Bedo]

Drew,

If the fungus is in the cemented surface then I can repair it if I can get the glass out. Burnished retainers suck..I know why manufacturers did that but that doesn’t make them nicer for it. It’s not period-correct, but I’ve turned burnished retainers down to remove the lens, effected the repair, and then rebuilt the burnishing with epoxy. If you want me to take a look send me a pm.

Take pgk’s advice up above first, tho.

-Jason

I am thinking I will go the UV light path. Someone off this board thought several hours in the kitchen oven at 150 deg F might help . . .Maybe , but I'll try sunlight first.


Noda: Don't think I'll take your path. I did that once quite a few years ago and it turned out well. I had gotten 10 Wollensak Oscillo Paragons salvaged from Tektronix oscilloscope cameras. Got them for $5 each! There was a heavy aluminum mounting collar threaded onto the lens barrel on each and cemented there in some way. Tried everything I could manage such as strong solvents and heat. Finally took them to a gunsmith. He chucked each lens cell into his lathe and cut the collars off. During the 1990s. I sold off 3/4 of them at camera shows for $50 each. Today i sold the last two on e-Bay for $220 each. I may not have asked enough!

I just don't want to do that with this fine looking antique lens, even if I can't remediate the fungus.

i do not think I will