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02-08-2013, 10:35 PM   #16
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QuoteOriginally posted by jatrax Quote
Sorry for the long post, I hope that explains my thoughts. And I will try to be more precise in the future instead of dashing off a careless reply.
But an informative post nonetheless, having a background in Biology myself (toxicology is my speciality) . One thing that I have never seen is fungi growing on the thoriated glass element of a SMC 50mm f/1.4 takumar, though I have seen fungi growing on ED glass with catastrophic results ( ED glass is generally softer than average optical borosilicate glass)


Last edited by Digitalis; 02-08-2013 at 10:41 PM.
02-08-2013, 10:48 PM   #17
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QuoteOriginally posted by wombat2go Quote
So how long does it take for a wet lens to become damaged by fungus?
I was in Thailand recently and took the Rikenon out of the cool hotel room 5:00 am for some shots whereupon it and the camera drastically fogged up.
I suppose this happens at each leaving of an aircon environment. Is the fungus growth cumulative or does it need some time to get started each time?
: thanks for the info so far
I would like to know the answer to this as well!!! I had the same issue when I brought a package from home today, it was sitting in the mail box (during a snow storm), I brought it inside the house and it immediately fogged up. The fog left after 10-15 min. and there was condensation on the outside that I tried with a towel.

Thanks!
02-08-2013, 10:52 PM   #18
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QuoteOriginally posted by Digitalis Quote
One thing that I have never seen is fungi growing on the thoriated glass element of a SMC 50mm f/1.4 takumar,
Mutant fungi!!!
02-08-2013, 11:00 PM   #19
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QuoteOriginally posted by wombat2go Quote
how long does it take for a wet lens to become damaged by fungus?
This depends on a number of factors: Environmental temperature being a rather critical one, up to a certain point heat generally accelerates the biological reactions needed for growth, as mentioned above moisture content and an ample nutrient base are also critical factors for growth. Assuming all criteria are at an optimum it can take a matter of hours for fungus to grow enough to be visible to the unaided eye. So If you have a lens that has been wet it is best to keep it in a dry, cool, open space. Many photographers who live in warmer latitudes where high humidity is common make use of commercially available silica desiccants to lower humidity and inhibit the chances of fungal growth*.


* just because a lens has Fungi growing on it doesn't suggest it has been permanently damaged. Sometimes simply cleaning the contaminated lens elements with a suitable (alcohol based) cleaning solution is enough. It is dependant on the kind of fungus that is growing on the lens, and the type of glass the lens is made of as some species of fungi can form compounds that can physically etch glass, As I have mentioned before, physically softer glass types such as ED and Fluorite are by far the most vulnerable to this kind of damage.


Last edited by Digitalis; 02-08-2013 at 11:18 PM.
02-08-2013, 11:04 PM   #20
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QuoteOriginally posted by Digitalis Quote
This depends on a number of factors temperature being a rather critical one, up to a certain point heat generally accelerates the biological reactions needed for growth, as mentioned above moisture content and a nutrient base are also critical factors. Assuming all criteria are at an optimum it can take a matter of hours for fungus to grow enough to be visible to the unaided eye. So If you have a lens that has been wet it is best to keep it in a dry, open space.
You really need to have a look at the lens in question. It is pictured on another thread and looks like it was stored in a steam room for a decade or two. Nasty.


Steve
02-08-2013, 11:16 PM   #21
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^ I think Steve is talking about my lens... haha!
Here's a quick link to it... it is really nasty... The whole front element is covered with fungus.

https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/214797-fungus-my-lens.html
02-08-2013, 11:29 PM   #22
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QuoteOriginally posted by stevebrot Quote
You really need to have a look at the lens in question. It is pictured on another thread and looks like it was stored in a steam room for a decade or two. Nasty.
I have seen worse than that, I had salvaged a large format Nikkor 360mm lens that looked like a degree student lab experiment. It had a coating of fungus on nearly all the elements - the lens was completely wrecked, but at least I got a really good watch glass to use when i'm in the lab:

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