Cleaning lens fungus

[chenick]

One of my SLR (ahem) lens appears to have fungus on the inside of the front element....

It's an early Series 1 Vivitar 70-210mm zoom. (version 2, constant F3.5 aperture) which I picked up cheaply.

Anyway, I thought someone might have a suggestion on cleaning it... Although I haven't noticed any ill-effect in pictures, I can't help thinking it may be affecting contrast.

I read somewhere that 'cooking' lenses with a light bulb for several hours can clear this up... Needless to say I'm not too keen on this without further info... nor am I too keen on disassembling it (even though it just appears to be the front lens element (see pic)

Any suggestions?

Cheers!!

Nick

 

[Pherdinand]

"Cooking" the lens (or using UV radiation, an alternative method) will not clean it from fungus - only kill the fungus so it won't grow further, with some luck. Cleaning it, if it's on the front element, should be easy - at least the procedure. Could be, however, that it's etched into the coating already, if it's there for long time. In that case, you might never be able to completely clean it.

Try with vinegar or even better, clean acetic acid diluted in water. Don't put it directly on the lens, coz it will sneak into the barrel; use it instead on a tissue.

 

[r-brian]

Actually, I read somewhere that Pond's cold cream takes fungus off of lenses. Put on the Pond's, let it set a little while, clean it off, repeat. Try over at the Classic Camera Repair Forum.

Brian

 

[Rob]

I think you are supposed to rub the cold cream in not just
let it sit there. It has a very mild abrasive in it.

 

[bmattock]

One word of advice - keep the lens away from your other lenses. Fungi spread by spores, and it has been said that one sick lens can infect others. Just FYI.

Best Regards,

Bill Mattocks

 

[chenick]

"Cooking" the lens (or using UV radiation, an alternative method) will not clean it from fungus - only kill the fungus so it won't grow further, with some luck. Cleaning it, if it's on the front element, should be easy [...]

Thanks for the suggestions guys - trouble is the fungus is on the inside of the front element - anyone know how accessible it is?
I see a notch or two in the retaining ring, plus there are some very small screws in the barrel itself... I'm not likely to touch the screws for fear of screwing it up, but if the ring is all that's keeping the front element in, I might see what I can do.

Cheers,

Nick

Fungi spread by spores, and it has been said that one sick lens can infect others.

Scary!!

 

[pshinkaw]

Most front elements come out by removing the nameplate first and then the retaining ring, On others you can just remove the retaininging. If possible use a rubber crutch-tip of the proper size. It may leave behind a mess of rubber bits, but reduces the risk of scratching the lens. A spanner will then be needed to remove the retaining ring.

I use masking tape to protect the glass near the spanner slots from scratching.

If it's just the front element, it fairly easy to fix. It can be a nightmare if it goes farther into the lens.

The most difficult part is re-assembly without a lot of dust.

-Paul

 

[Sonnar Brian]

I took fungus/fog out of a first generation Vivitar Series I 70-210 for a friend. It had a retaining screw to hold the name-ring in. I think they were under the rubber grip, could be wrong on that. Look for some set-screws over the retaining ring, be sure to back them off before removing the front ring or "OUCH!" will occur.

 

[Sonnar]

Putting the lens apart, cleaning the glasses is the only solution really helps. Usually this needs the right tools, costs money and isn't always applicable for a cheap lens. I've seen lenses with scratches inside (decomposer didn't know the coating inside can be softer than outside?), or totally dejusted lenses after rebuilding. Beware of!

Often you can clean the fungus but it has eroded the coating, this will be no big improvement, if any.

If the fungus grows between two coupled elements it's expensive til hopeless. Even it's not impossible dividing and re-gluing them with the right appliances.

A few tiny spots on a front lens - well, burn it with an UV-lamp for a few days, hope that the fungus will die, forget it (if the pictures are well)

I once had fungus with two small well to maintain Canon RF lenses. One was the "milky type"- lens suffered contrast - impossible to remove completely without doing further damage. Next was a very fine "spider web" growing form the outer zones. Since "UV-burning" wasn't a help, it is a true collector item and I have a good repairman on hand, I let him do the stuff and paid 40 USD for an excellent job. Both lenses were 6-element double Gauss and the fungus occurred at the 5th, non-coupled element.

In the last cast I had hope for better outzone sharpness after this operation, but this wasn't fulfilled though the glass looks like new now. Even best maintenance can't improve a 40-50 year old design... 🙂

cheers...

 

[oftheherd]

One word of advice - keep the lens away from your other lenses. Fungi spread by spores, and it has been said that one sick lens can infect others. Just FYI.

Best Regards,

Bill Mattocks

This echos what I have always heard. Even putting it on your camera and adjusting focus (or even more so, zooming with an SLR) could drive spores into the camera and from there into other lenses. Unhappy prospect!

 

[fraley]

Nick,

Speaking as one not too gifted at Do It Yourself, I would try rotating the outer ring - you may be able to use modified calipers if you don't have a spanner tool. The front element should be fairly simple to remove and clean. I personally would stop there..

 

[kanirasta]

Problem with Canonet QL17

Problem with Canonet QL17

I have one Canonet QL17 that I got incredible cheap because it wasn't working and the lens had fungus.

I managed to open it and make it work (my first try at camera repair). But I also wanted to solve the fungus problem, so I tried to clean it with Stop Bath (which is Acetic Acid or so I 've been told).
The fungus didn't clear, so I left the elements submerged in the liquid for a day.

The problem is some elements are just like they were (fungus and all) but the front element is VERY cloudy, just like ground glass. You almost can't see through it. It was the worse infected but it still rings strange that the remainding elements had no problem with the acid and this did?

Or maybe it is that the fungus changed state now clouding the lens?

Was it a mistake to submerge the elements on acetic acid?

 

[35mmdelux]

DO NOT use the same cleaning cloth used to clean fungi on your other lenses, unless you want to spread the disease.

 

[kanirasta]

So. No one can help me on this?

 

[John Robertson]

One word of advice - keep the lens away from your other lenses. Fungi spread by spores, and it has been said that one sick lens can infect others. Just FYI.

Best Regards,

Bill Mattocks

Yup, a friend a few years ago sent a lens with fungus to Leica UK, it was politely returned unopened, with a note saying they dont take infected lenses in and suggesting a company in London which might help.

 

[petebown]

I have one Canonet QL17 that I got incredible cheap because it wasn't working and the lens had fungus.

I managed to open it and make it work (my first try at camera repair). But I also wanted to solve the fungus problem, so I tried to clean it with Stop Bath (which is Acetic Acid or so I 've been told).
The fungus didn't clear, so I left the elements submerged in the liquid for a day.

The problem is some elements are just like they were (fungus and all) but the front element is VERY cloudy, just like ground glass. You almost can't see through it. It was the worse infected but it still rings strange that the remainding elements had no problem with the acid and this did?

Or maybe it is that the fungus changed state now clouding the lens?

Was it a mistake to submerge the elements on acetic acid?

My guess is the acetic acid was too strong and has etched the glass and/or the lens coating. Personally, I wouldn't have left the lens in acid that long. I would have used the acid for no more than a few minutes. The lens could be re-polished, but this would be very expensive.

 

[JohnTF]

So. No one can help me on this?

Since goodwill and others sell broken QL17's daily , and am pretty sure Igor at IgorCamera.com has a pile of "needing love" fixed lens RF's close to the dumpster stage, get another cheap one and swap the parts to make one good one, you are almost sure to come out ahead.

And just be glad it was not some seriously priced glass you soaked in whatever you used.

Even weak acids in rooms with poor ventilation can facilitate a lot of corrosion and rust, have seen the chrome eaten off cameras and enlargers with pitted metal from stop bath in a bottle with evidently a leaky screw top.

Some people, especially depending on climate, store firearms, and other equipment in cabinets with a "golden rod" heating element which keeps the temperature inside a bit above ambient to chase away humidity.

As far as using UV to sterilize, am not entirely sure UV will penetrate beyond the outer layer, as many types of glass will not transmit UV.

To the OP, if it were my lens, and if I could get a technician to clean the outer element for a reasonable price, I would weigh the value of the lens to you and decide. It does not sound like a simple screw off outer element?

Regards, John

 

[kanirasta]

Thanks a lot for the answers!
What do you think about trying to polish the glass with tootpaste?
If it's already lost it can't hurt right?

 

[Joao]

I have one Canonet QL17 that I got incredible cheap because it wasn't working and the lens had fungus.

I managed to open it and make it work (my first try at camera repair). But I also wanted to solve the fungus problem, so I tried to clean it with Stop Bath (which is Acetic Acid or so I 've been told).
The fungus didn't clear, so I left the elements submerged in the liquid for a day.

The problem is some elements are just like they were (fungus and all) but the front element is VERY cloudy, just like ground glass. You almost can't see through it. It was the worse infected but it still rings strange that the remainding elements had no problem with the acid and this did?

Or maybe it is that the fungus changed state now clouding the lens?

Was it a mistake to submerge the elements on acetic acid?

I made the same mistake and had a similar outcome; fortunately I was trying to remove fugus stains from a faulty Domiplan lens (it was already severely damaged so I used diluted vinegar overnight as an experiment). The lens surfaces were both transformed in groundglass!
Lesson: vinegar causes less damage in my stomach than in my lenses...
Regards
Joao