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02-27-2012, 11:16 AM   #16
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Just a thought... WR (weather resistant) is not the same as weather-proof.

I shoot in light rain and snow with my non-WR lenses and so far no fungus. I keep silica gel packs in my camera bag, and rotate them out frequently. Of course, the humidity in the NE USA is not like in more tropical locales.

Is there something like a Lens Skin for the 50-135?

02-27-2012, 11:35 AM   #17
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QuoteOriginally posted by Reportage Quote
actually...has there ever been a controlled experiement to measure just how weather sealed a lens advertised as such is?

Is there an international standard for defining the lens weather resistance capability?

Would be interesting to know whose brand lens has the best weather sealing....and it looks like india could be one the best places to test it.
Good question - I was asking myself the same. When something is sold as WR then how long can it resist in a humid environment? Does WR mean that your lens has to be always mounted on the lens? What's the difference in handling of a WR lens compared with the handling of common lens in a humid environment?

I was afraid that something like this may happen in a tropic environment - that's why I spend quite some money to have a WR equipment.

Today I've called a Pentax service partner - they first told me that they can't believe that there is Fungus in the lens. First they where like "Uhm..Fungus..what's that?" ;-) They told me to have lenses which fell into water and those lenses had corrosion/rust issues. But never Fungus. They also don't take my lenses for repair as they are afraid that their equipment gets contaminated. But I've read on a German forum that some independent repair centers/private people to this job. But I'm afraid they are not able to deal with a WR lens with special sealings.

QuoteQuote:
Build the dry cabinet you mentioned and take out your equipment only when shooting. Your fungus will not increase if you keep the humidity lower than the dormant level.
Well, now my lenses are exposed to European humidity only. I read that the dormant level is about 60% so you have to keep in under this value. Some users said if the humidity is too low (under 30% when I remember right) this can also damage your lens coating. Actually I don't know the humidity at home - I've to check and if needed build such a cabinet.

QuoteOriginally posted by luftfluss Quote
Just a thought... WR (weather resistant) is not the same as weather-proof.

I shoot in light rain and snow with my non-WR lenses and so far no fungus. I keep silica gel packs in my camera bag, and rotate them out frequently. Of course, the humidity in the NE USA is not like in more tropical locales.

Is there something like a Lens Skin for the 50-135?
Absolutely agree that WR doesn't mean weather proof. The lenses where never exposed to rain too long. But when wet air destroys a weather resistent lens already I'm not sure how much you can rely on such a feature.

Dunno if there's a lens skin - but what I read out of the other posts is that the weak part is the back of the lens - when it's not mounted on the camera.

Last edited by davidt; 02-27-2012 at 11:44 AM.
02-27-2012, 11:50 AM - 1 Like   #18
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QuoteOriginally posted by davidt Quote
QuoteQuote:
Bath them in strong UV light.
This does only work to prevent fungus - it doesn't let it disappear, doesn't it?
Strong UV light should kill the existing fungus with a long enough exposure. It won't make it disappear, but it should make it appear to recede a bit, as the filaments become dessicated when dead (in a dry environment, anyway). I don't know if UV from sunlight is enough to kill spores, probably not, so it probably won't prevent new fungus from starting.
02-27-2012, 11:57 AM   #19
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QuoteOriginally posted by Philoslothical Quote
Strong UV light should kill the existing fungus with a long enough exposure. It won't make it disappear, but it should make it appear to recede a bit, as the filaments become dessicated when dead (in a dry environment, anyway). I don't know if UV from sunlight is enough to kill spores, probably not, so it probably won't prevent new fungus from starting.
Thanks for that! Good to know there is at least something I can do. Will try asap...

02-27-2012, 12:17 PM   #20
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Yep. If using sunlight it can take several days of exposure. If you can get ahold of a UV lamp of some kind (shortwave, I think. Anyone verify?), that might be easier as you could expose it around the clock.
02-27-2012, 12:18 PM   #21
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It would seem to me some company could make a few bucks with a premium o ringed travel/storage case for expensive photo equipment that had provisions for a dry air, CO2 or inert gas atmosphere flush when put up for storage. I don't believe fungus grows rapidly or from an occasional drop of water, but from the spores and long term sitting in humid air.. There is available compressed dry gas small cylinders used for the electronics and precision work industries already.

This might be ideal as "a dry storage cabinet" that travels as half the world is in high humidity zones.

Just a thought.

Last edited by Phil1; 02-27-2012 at 12:27 PM.
02-27-2012, 06:23 PM - 1 Like   #22
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Here is a travel tip that I've used offered to me by some award winning photojournalists I met years ago. After shooting and you're back in the hotel room or any place with an electrical socket, use a small hairdryer to blow warm air on the lens. Then keep your lens in a zip lock bag, expelling all the excess air and put in some silica gel packets.
02-27-2012, 09:50 PM   #23
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Random comments about fungus

First - silica gel does work - if it is dry and if the space is sealed to limit the amount of moisture being adsorbed and if sufficient time is allowed. Some companies offer packets with a color-indicating silica - usually blue when dried, pink when not dry.

For what it's worth, I'm familiar with a system to provide a (nearly) continuous stream of dry air to an instrument - an air compressor forces air through a bed of silica gel. Periodically (once a day, I think), the air is automatically vented away from the instrument (but still through the silica) and the silica heated to about 300 F, which dries it. After the drying cycle, the silica is allowed to cool, and the air again pumped through it into the instrument. As I recall, it cost us about $8000, without the compressor. Supposedly will last twenty years. Could probably be built for a few hundred US$. Maybe $1000.

Yes, UV light will kill fungus. And yes, short-wave UV is much more effective than sunlight or long-wave UV. But short-wave UV can also cause retinal burns, cataracts, sun burns, skin cancer, and blindness. Watch yourselves folks. Be certain you understand what you're doing.

As mentioned above, for at least some types of fungus, dryness doesn't really kill the spores - it just causes growth to stop. Yes, fungus spores are (nearly) everywhere. They are marvelously versatile little pests.

02-28-2012, 06:25 AM   #24
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QuoteOriginally posted by Phil1 Quote
It would seem to me some company could make a few bucks with a premium o ringed travel/storage case for expensive photo equipment that had provisions for a dry air, CO2 or inert gas atmosphere flush when put up for storage. I don't believe fungus grows rapidly or from an occasional drop of water, but from the spores and long term sitting in humid air.. There is available compressed dry gas small cylinders used for the electronics and precision work industries already.

This might be ideal as "a dry storage cabinet" that travels as half the world is in high humidity zones.

Just a thought.
Correct. Looks like this is what the Pros are using: Camera cases by Pelican - carrying - shipping - waterproof

QuoteOriginally posted by creampuff Quote
Here is a travel tip that I've used offered to me by some award winning photojournalists I met years ago. After shooting and you're back in the hotel room or any place with an electrical socket, use a small hairdryer to blow warm air on the lens. Then keep your lens in a zip lock bag, expelling all the excess air and put in some silica gel packets.
Thanks for the tip!

QuoteOriginally posted by jford Quote
First - silica gel does work - if it is dry and if the space is sealed to limit the amount of moisture being adsorbed and if sufficient time is allowed. Some companies offer packets with a color-indicating silica - usually blue when dried, pink when not dry.

For what it's worth, I'm familiar with a system to provide a (nearly) continuous stream of dry air to an instrument - an air compressor forces air through a bed of silica gel. Periodically (once a day, I think), the air is automatically vented away from the instrument (but still through the silica) and the silica heated to about 300 F, which dries it. After the drying cycle, the silica is allowed to cool, and the air again pumped through it into the instrument. As I recall, it cost us about $8000, without the compressor. Supposedly will last twenty years. Could probably be built for a few hundred US$. Maybe $1000.

Yes, UV light will kill fungus. And yes, short-wave UV is much more effective than sunlight or long-wave UV. But short-wave UV can also cause retinal burns, cataracts, sun burns, skin cancer, and blindness. Watch yourselves folks. Be certain you understand what you're doing.

As mentioned above, for at least some types of fungus, dryness doesn't really kill the spores - it just causes growth to stop. Yes, fungus spores are (nearly) everywhere. They are marvelously versatile little pests.
I'm about to order a short-wave UV lamp. I will put the lamp and lenses in a dedicated room and air the room after a longer drying-session to get rid of the ozone, similar to the usage of laser printers. Right?
02-28-2012, 08:09 AM   #25
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QuoteOriginally posted by philbaum Quote
Build the dry cabinet you mentioned and take out your equipment only when shooting. Your fungus will not increase if you keep the humidity lower than the dormant level.
Agreed, dry cabinet, use equipment only when required, condy's crystals my be an option in bag, not silca gel.
02-28-2012, 10:27 AM - 1 Like   #26
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I'm not too sure if a one short warm up with a hair dryer removes the humidity permanently. It may damage the fungi spores with the heat and certainly dry any condensed moisture. Remember mushrooms love a hot house. I like the UV light deal. Many household washer dryers have or had this feature. Dry effective silica gel in a Pelican case should work too. You can dry out the silica gel with a hair dryer or oven if available. That is supposed to work well so you can "recycle" the silica gel till the packets fall apart if you wish.

Recycling silica gel:
How to Recharge Silica Gel | eHow.com
02-28-2012, 11:00 AM   #27
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Regarding condy crystals aka potassium permaganate: It is an oxidizer. As kids we used it with another kitchen chemical and made a light duty explosive. This might present problems with air travel and I sure do not want a heavy oxidizer in with my camera gear though it may absorb humidity. Just a heads up.

Potassium permanganate - Wikipedia, the free encyclopedia
02-28-2012, 04:01 PM   #28
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Are the potassium permaganate crystals more effective than silica gel? I remember potassium permaganate using in some experiments with my childhoods chemistry kit.

Your arguments sound reasonable Phil1 - I don't think I want an oxidizer next to my gear.
02-28-2012, 04:05 PM   #29
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At one point in time I was going to try to set up a UV lamp in an attempt to kill some fungi in a lens. I never did try it though so I can't report on results.
02-28-2012, 06:08 PM   #30
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Re: Silica gel: This has been used for humidity reduction purposes since WWII in electronics, instruments and optical equipment in shipping and storage. Pretty cheap and fool proof. Not much of a need to look elsewhere is my bet and it can be reused many times.

There is a material that is used in protecting metals and equipment from humidity and oxygen damage. It is embedded in special paper and it forms a vapor barrier around the item that it is wrapped in. It has replaced waxes and cosmoline in shipping and storage protection. I would be really concerned about using it on optics. I just don't know if it would react to the lens coatings and plastics in photo gear.

Link:
Vapor Barrier_Paper

More on this stuff on Google if you dare.
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