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05-17-2012, 05:27 AM - 2 Likes   #1
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A definitive lens fungus thread.

Having just experienced my first lens with fungus I thought it might be wise to pool our collective knowledge on the subject. Attempts to find accurate and widely accepted facts about fungus across many online photography resources only seemed to further 'cloud' the issue, ergo why not use this thread to discuss experiences, truths, myths and help build a quality general knowledge base on lens infection.

Specific points for discussion might be might be:
Cause.
Prevention.
Cure.
The mechanics of cleaning regards specific lenses.
Facts.
Myths.
Not sures, and any other expertise this forums users can offer.

I do this because the entire internet hasn't made it's mind up on fungus, but it's science- there has to be evidence based truths that we can all work from.

I'll start the ball rolling. Can fungus infect another lens in your collection ? You know, you pick up a second hand piece of glass with a small blob in it and think 'Ok, I'll clean that soon enough.' but are we to treat it as a contagion risk and banish it from the house ? Or is that just a widely held fear with no basis in real world fungus behaviour.

For me if your lens collection is kept in a way to prevent fungus, introducing one that's fallen foul cannot possibly have an effect. It's not how spores transfer that's the risk here, it's the environment and condition that they may find a foothold for growth in. It's why my bath taps have mould around them and my bed in the room next door doesn't. Spores are in the air in both spaces, but only the wet warm bathroom can be an efficient host that leads to growth. But I can't catch fungus off the taps, so how can a lens ? (My bath isn't that dirty by the way).

05-17-2012, 10:33 AM   #2
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I know this may seem a joke, but this is a real case and I tried to arrange it to your outline. Hope this helps.

Subject Lens: Super Takumar 50mm F1.4

Cause: Actual Unknown. As found in lens when received via Ebay and as stated prior to sale.
Prevention: Not storing in lens case for ten years with no humidity control. Lens was from Florida and with original owner for over 22 years had been traveling with lens.
Cure: UV bath prior to dis-assembly to limit living spores and infected group covered in a 1:10 GSE:water (grapefruit seed extract) to stop spores from scattering and killing establish colony, if any remained.

The mechanics of cleaning regards specific lenses.

Front name ring removal - shroud screws 3 removed - Group spanner ring counter clockwise for removal - Inner lens separated from group - infected element soaked in GSE solution for ten minutes - rinsed - optical cleaning - adjacent lens also cleaned and process same as infected - element mount and retainers also cleaned and dried completely in low heat - work area cover replaced - all parts dusted - returned to group - group remounted - shroud returned - name ring secured

Facts: Low level growth due to early discovery of colony. Prior to actual investigation of infection, the lens was enclosed in dry bag with desiccant after cleaning for a week and later exposed to UV lamp to assist in rendering the spores neutral.

Myths: This infected lens would not have been able to infect other lenses as the infected area was not directly able to access the only air space which would be the aperture diaphragm compartment. The actual infection was only found between the second and third elements and the spores would be contained within that space.

Proliferation Danger Assessment
: If infection were in the space of the diaphragm compartment and the colony had developed to the point were the air space was near full, the chances of spores traveling into the control armature space and beyond the mount would have increase the chances of cross lens infections. If spores infected the mirror box of camera and the spores transferred to there lenses due to action of mirror as the casting mechanism of the spores, uninfected lenses would have been infected and would probably show up in the diaphragm compartment of the new host lens.


Sort of reads like a movie?

Last edited by MysteryOnion; 05-18-2012 at 10:57 AM.
05-17-2012, 10:49 AM   #3
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Well I'll contribute to Myth. you don't need any lenses with fungus to get it. the spores are in the air everywhere, it's just whether or not environmental conditions are favourable to growth. humidity and warmth in dark areas are your enemy, not already infected lenses. Keep humidity low and storage ventilated and you should be fine (not always easy - if you live in a tropical climate at some point or another you will likely have the problem)
05-17-2012, 10:57 AM   #4
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I had no idea! Thank you for raising the issue LondonRob and for the thorough description of a solution, MysteryOnion. Sounds like a very practical suggestion, eddie1960.

05-17-2012, 01:13 PM   #5
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What irks me is that every post across many many sites regards cross contamination starts with "I've heard...." or " A guy told me....." or "Dude ! Bin that lens it WILL infect all your others !" but not once has anyone cited an actual incident of this. (Not that I've found) My gut feeling is it's just not likely. It's conditions that convert spores into growing cultures not the presence of the spores alone. The internetz also says spores are everywhere and as someone who makes sour dough starters and understands the history of yeast and baking I can see why this is.

Or have I got this totally wrong and the lens I'm looking at now with fungus in it is stealthily dropping it's bombs all over my k5 and glass on the shelf over there. A perplexing thing for sure.
05-17-2012, 02:37 PM   #6
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QuoteOriginally posted by London Rob Quote
What irks me is that every post across many many sites regards cross contamination starts with "I've heard...." or " A guy told me....." or "Dude ! Bin that lens it WILL infect all your others !" but not once has anyone cited an actual incident of this. (Not that I've found) My gut feeling is it's just not likely. It's conditions that convert spores into growing cultures not the presence of the spores alone. The internetz also says spores are everywhere and as someone who makes sour dough starters and understands the history of yeast and baking I can see why this is.

Or have I got this totally wrong and the lens I'm looking at now with fungus in it is stealthily dropping it's bombs all over my k5 and glass on the shelf over there. A perplexing thing for sure.
i wouldn't worry about cross contamination. odds are every lens you own has a few spores inside, just don't store them in the bathroom next to the shower.

for the infected one though you definitely want to stop growth asap, and a cleaning if the lens is worth cleaning fungus will damage coatings
05-17-2012, 03:27 PM   #7
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QuoteOriginally posted by London Rob Quote
What irks me is that every post across many many sites regards cross contamination starts with "I've heard...." or " A guy told me....." or "Dude ! Bin that lens it WILL infect all your others !" but not once has anyone cited an actual incident of this. (Not that I've found) My gut feeling is it's just not likely. It's conditions that convert spores into growing cultures not the presence of the spores alone. The internetz also says spores are everywhere and as someone who makes sour dough starters and understands the history of yeast and baking I can see why this is.

Or have I got this totally wrong and the lens I'm looking at now with fungus in it is stealthily dropping it's bombs all over my k5 and glass on the shelf over there. A perplexing thing for sure.
Lets jump further back to the spore... which? If someone would shed a little light on the type of spores that are most able to grow in the extreme conditions of a lens... extreme, but not impossible.

Now remember that a lens is not a hermetically sealed vessel. For instance if you spray lens cleaning liquid to the front element of a lens... one that is not built to be weather resistant, you would notice that the liquid will soak into the edges of the element and even soon the element will fog from it. So the spores life has a chance to easily make a home inside the lens. Also, if the lens was not slightly vented or loose, the lens would have some pressure issues due to temperature and air pressure over time that may effect the lens. The milling of a lens is precise, but not to the point were the fit is so tight that temperature changes risk the cracking of an element. If you have ever serviced a lens and slipped the element into its proper cavity, you might have observed the lens slowly slide in by its own weight and effect of the released of air around it. Zoom lenses are the more hospitable host as the air is often exchanged with each trombone of the groups. So conditions are there for certain lenses and the other conditions come along or not.

The cleanliness of the assembly plant more often vary and if memory serves, they check for optical impairment and not check every millimeter of the housing... sorry, we need not go that way.

Fungus in microscopes was my first experience... pain in A.. to clean too.

Last edited by MysteryOnion; 05-18-2012 at 11:04 AM.
05-17-2012, 10:05 PM   #8
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QuoteOriginally posted by MysteryOnion Quote
Lets jump further back to the spore... which? If someone would shed a little light on the type of spores that are most able to grow in the extreme conditions of a lens... extreme, but not impossible.
Aye...and there's the rub. I am not a mycologist, but I do have pretty good background with moldy lot. Yes, fungal spores are everywhere and yes, conditions must be appropriate for an infestation to occur. The critical point is that most fungi would have a difficult time making a living on the surface of your average lens.

That being said, when you have an infected lens, you basically have a culture dish containing spores with proven infective capacity. I, for one, am unwilling to help nature on its way by providing additional media for propagation.

As for risk...I am lucky to live in a part of the world (Pacific NW of North America). We get a lot of rain, but humidity is generally moderate and temperatures tend to be cool. I have never seen fungus on a locally purchased lens. The lenses that I have had problems with were eBay purchases from Texas, Mississippi, Florida, and Georgia. I try to avoid sellers from the southern U.S. as a result.

Like @MysteryOnion, my first experience with fungus and optics was with microscopes. I was on Barbados several decades ago at a biological field station as part of a specimen collecting tour (algae). We were very pleased to note on our arrival that the lab was well-equipped with almost new Wild and Leitz microscopes. We were sadly informed that all had been ruined by fungus and awaiting some sort of service to attempt a salvage. What a shame!


Steve

(...treats infested lenses as if they were infected biological material...)

05-18-2012, 02:49 AM   #9
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So as to add to this thread... a little list of
Fungus Protocols:

1. Detection - Bright light? Sunlight? Bright defused light?

2. Assessment - Too small? Outside field of view?

3. Severity - when?

4. Minimization - UV - Naptha?

5. Removal - Soap - Detergent - disassembly?

6. Prevention - desiccants - rice - silaca?

please edit list and add stuff in as well as discussions on the points.
05-18-2012, 05:02 AM   #10
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Good idea ...

QuoteOriginally posted by RM Barker Quote
I had no idea! Thank you for raising the issue LondonRob and for the thorough description of a solution, MysteryOnion. Sounds like a very practical suggestion, eddie1960.
I'm in ... what about expanding to other isuues later ... like re-lubing, removal of stuck filters, lens surfaces (do's & don't), etc.
05-18-2012, 07:41 AM   #11
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QuoteOriginally posted by MysteryOnion Quote
So as to add to this thread... a little list of
Fungus Protocols:

1. Detection - Bright light? Sunlight? Bright defused light?

2. Assessment - Too small? Outside field of view?

3. Severity - when?

4. Minimization - UV - Naptha?

5. Removal - Soap - Detergent - disassembly?

6. Prevention - desiccants - rice - silaca?

please edit list and add stuff in as well as discussions on the points.

I would suggest deleting "removal" from the list or at least qualifying the process in regards to expected result and suitability for resale. I have two recent lens purchases advertised as fungus free where there was ample evidence of etching of the glass/coatings from fungus and/or hazing from the cleaning process.

While the owner of a fungus-infected lens may be able to manage a cure they are happy with, to resell such a lens as fungus free is not ethical. It is similar to the practice of curing rusted car fenders with fiberglass and bondo.


Steve
05-18-2012, 08:16 AM   #12
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OK... so like this now.

or should it be more a flowchart?


1. Detection - Bright light? Sunlight? Bright defused light?

2. Assessment - Too small? Outside field of view?

3. Severity - when?

4. Minimization - UV - Naptha?

5. Prevention - desiccants - rice - silaca?

please edit list and add stuff in as well as discussions on the points.

Detection... of Fungus or Prior Infestation.

which brings us to techniques in analysis of surfaces as part of the Detection.

Removal... Removal of fungus to optimize the lens for use. Removal of fungus and assess damage for value assignment or devalue.


So London Rob, are we going in the right direction and should this thread be tacked on a different area to attract more input?
05-18-2012, 11:16 AM   #13
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Oh the thread can go in any direction posters take it. My aim and only aim was to have a central thread for a collective pool of fungus experience and knowledge, and hopefully facts. So much about photographic equipment is rightly controlled by maths and science but many aspects of fungus discussion seemed to be rooted in hearsay and old wives tales. I just wanted to re-introduce the idea of fact based evidence to how we react to fungus.
for the record I cleaned my A 50mm f1.7 earlier today. Very very simple:

Tiny spot seemingly in the middle of the lens next to the aperture space so I determined it was the rear element. (I shut the aperture and in vanished)
So removed the 5 rear screws using a cross head ph00 screwdriver borrowed off an IT guy.
Lifted off the k mount, not the aperture ring, giving enough space to grip the rear element barrel and unscrew it like you would a bottle top.
Fungus was like a biro dot on the glass nearest the aperture so swabbed it off with vinegar then Windowlene then dry buff.
Put it back together.

I have no concern whatsoever mounting this virtually unused classic lens on my k5 !
05-18-2012, 01:28 PM   #14
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Prevention

A lens inventory should be made and the high use, less valuable lenses may not require any really special care particularly if one is in a dry and cooler climate than say Florida or in the tropics. High value, less often used lenses and gear it might be worthwhile to consider some special care.

It seems to be a given that the fungus spores are everywhere and that they require a humid atmosphere and a warmish temperature range.

Addressing the atmosphere side of the equation presents a number of options. The free exchange of air should be controlled by an air tight method.

A: Zip Lock freezer plastic bags. There are inexpensive, are see-threw, low cost, reusable, low weight, durable and are about 99.9% air and water tight. They also take up little space in storage and one can wrap a lens and insert it in the factory storage case or pouch for storage and travel. They come in many sizes and are available in most any super market. OK for air travel.

B. A water tight Pelican style case. Great for storage and travel all though every time it is opened the atmospheric lock will be broken. Spores and humidity can enter. These are usually sealed by an o ring or foam gasket method. Everything you have in the case will get a fresh load of humidity and spores. OK for air travel.

C. Storage cabinet. This method slows down the exchange as most cabinets are not air tight but do a good job of excluding dust and spores. They don’t do too much for humidity by themselves. Again every opening of a cabinet brings in fresh spores and humidity too. Great information on engineered "dry cabinets" can be found here: http://www.totechamerica.com/productincludes/faq.php

Keeping that enclosed space of your choice really air-dry and spore free:

A. Desiccant (silica gel) bags. These are inexpensive and dry the air out by absorbing the water molecules similar to a sponge. OK for air travel. Obviously they have an absorbing limit and you can bet old ones have reached their effective maximums and should be replaced with dry fresh ones or you are fooling yourself. Many have saturation indicators on the bag to warn you the max has been reached.
(Sorb-It packaged silica gel desiccant is made from amorphous silicate. It is a hard, translucent material with an extremely high capacity for moisture at temperatures below 75F and at humidity levels above 40% RH. Sorb-It is designed to control moisture levels within packaged products. The function of Sorb-It when controlling moisture is like that of a tiny sponge with millions of microscopic pores. Under very low humidity conditions, a small amount of water vapor will be adsorbed in the smallest pores. As humidity increases, the large pores will begin to fill. Unlike a sponge, however, Sorb-It remains dry and free-flowing, even at maximum adsorption capacity) For information:Desiccant City: Sorb-It Silica Gel Desiccant bags can be refreshed by warming and driving the water out. You can Google desiccant recycling.

B. Rice: Probably better with kung pao chicken but it does have a small water absorbing ability. Some restaurants used to put it in the salt shakers before they start adding anti stick chemicals to salt grains.

C. Camphor: Sometimes used to displace water molecules in machinists tool boxes. This would keep iron and steel tools from rusting. I am not sure what the camphor vapors can do to plastics, electronics or lens coatings. Personally I would avoid it for camera equipment.

D. Atmosphere displacement: If an air tight housing (Zip Lock bag) is used you might consider and atmosphere flush of nitrogen, or dry compressed air. You can obtain dry air in pressure cans that are used for watch making, electronics and such. Dry air is also available in SCUBA dive tanks if in the field if you do under water photography. I think I would avoid CO2. There are some studies of fungi stimulation in CO2 atmospheres. You might consider a wine preservation gas. This one is reportedly a nitrogen and argon mix and is used to displace oxygen in wine bottles to stop oxidation and degrading. http://www.wineenthusiast.com/wine-enthusiast-private-preserve-wine-preserva...CJ You obviously cannot take a pressure cylinder aboard an airplane.


E. Ultra violet light: This might be used for large cabinet storage. They use UV lights in washing and dryer machines to sterilize. UV light is also used in water reclaimation plants to kill bacteria and such. This should kill any cabinet spores. A small UV light would improve a not-so air tight cabinet. A paper on UV light used for building fungi control: http://aem.asm.org/content/67/8/3712.full

Last edited by Phil1; 05-19-2012 at 06:05 PM.
05-18-2012, 03:29 PM   #15
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without constant maintenance on the desiccant to ensure its working as it should the 3 options (particularly the first 2) can promote growth as well, certainly when you put the lenses in there will be spores, desiccant will prevent growth for a while but as humidity grows (and heat) the dark environment is an almost perfect fungus lab
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