Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
02-26-2012, 05:46 PM   #1
Forum Member
davidt's Avatar

Join Date: Apr 2009
Location: Vienna
Posts: 50
Fungus in my DA* 16-50mm & DA* 50-135mm

WR was one of the major reasons to buy a Pentax SLR. But after spending more than 1 year in India I'm trusting not too much in WR anymore. Lately I've noticed quite some Fungus in my DA* 16-50mm and DA* 50-135mm. From time to time those lenses got wet due to a sudden Monsoon rain but I have always dried the lenses right afterwards. And when not being used they where stored in my camera bag with lots of silica gel bags. So I don't understand how this could have happened...

I don't understand how a lens which is sold as WR does not survive the moisture in the tropical zone. Fortunately the IQ is still very good, especially with the 50-135mm.

Do you have any tips how I should proceed - Is it possible to save these lenses from dying a painfull death?
When Pentax claims the lenses are weather-resistent, do they also guarantee that such a case can't happen?

02-26-2012, 06:02 PM   #2
Pentaxian
JinDesu's Avatar

Join Date: Jun 2011
Location: New York City
Photos: Gallery
Posts: 5,626
shine sunlight on them for prolonged periods of time - keep them dry and hot (i believe fungus is cool and dry).

i can only imagine fungus getting in when the lens is unmounted - otherwise the seals are quite resistant to water. Sooooooo... either you didn't keep them dry enough or your lens sealing isn't working. Except you'd probably notice the sealing not working if you used them in the rain.

i was gonna say the zoom action may be part of the problem, but i believe the 50-135 is internal zoom
02-26-2012, 06:09 PM - 1 Like   #3
Site Supporter




Join Date: Jun 2009
Location: Indiana PA USA
Posts: 1,346
I wish I could offer a solution, but I'm afraid I can't. I can only say that you shouldn't be too harsh about the "weather resistant" not standing up to an Indian monsoon. I use fungus in my research and am amazed at how robust they are and how little it takes to get some growing.
Also, about your silica gel packets - are you certain they were dry? Such packets can only adsorb a certain amount of water, so to be effective, the packet and the object to be kept dry must both be in an air-tight container and the packet must be dry. Most packets can be dried in a home oven at about 275 F for several hours - but then you have to store them dry.
Good luck with your lenses.
02-26-2012, 06:09 PM   #4
Veteran Member
Docrwm's Avatar

Join Date: Sep 2010
Location: Somewhere in the Southern US
Photos: Gallery | Albums
Posts: 11,275
Prolonged exposure to UV - preferrably sunlight. Ditch the silica gel as once its saturated it can serve as the source of moisture for mold.

02-26-2012, 06:09 PM   #5
Site Supporter
Ex Finn.'s Avatar

Join Date: Nov 2007
Location: Southern Maryland.
Photos: Gallery | Albums
Posts: 6,292
Bath them in strong UV light.
02-26-2012, 06:11 PM   #6
Veteran Member
creampuff's Avatar

Join Date: May 2007
Location: Singapore
Photos: Gallery
Posts: 3,955
Take a tip from those of us who live in the tropics with very high humidity. Keep your gear in a dry case or a dehumidifier where the RH can be adjusted to about 40%. Using silica get is next to useless and don't forget it is easy for a camera bag to retain moisture.

So don't blame a lens being WR or not, fungal spores are everywhere and fungus will grow when there is high ambient humidity and warm conditions. Blame your ignorance in keeping your equipment adequately dry.

BTW, putting a lens in the sun won't always stop the fungus from growing. If it is already there, you can be sure the spores are still present in the lens. A lens would need to be properly opened up to be cleaned and disinfected and collimated for exact focus when reassembled. If left unchecked, the fungus will etch into the lens coating making the lens junk.
02-26-2012, 06:12 PM - 1 Like   #7
Site Supporter
jatrax's Avatar

Join Date: May 2010
Location: Oregon
Photos: Gallery | Albums
Posts: 10,770
Getting actual water inside is not the only way to get moisture inside a lens. If you are working in a humid environment, the air will have a high moisture content. And air is pumped in and out as you zoom despite the seals. Humidity by itself is not always a problem, but if you take a lens full of warm humid air into air conditioning you will get condensation which over time can build up and cause the same problems that getting actual water in would cause.

You might try a drying cabinet, just a cabinet or a box with a light bulb inside is enough to dry things out over time. I make a point of putting my gear in a warm dry area when I come in from the wet, and I mean very warm, not just room temperature. Key is to have the air warmer and dryer than that in the lens so the humidity gets pulled out.

Fungal spores are present in the air we all breath, so keeping fungus out is a myth. You have to control the environment that allows the spores to grow. The spores are already in the lens, the first time you zoom in or out. Keep out the moisture and then cannot grow.
02-26-2012, 07:39 PM   #8
Forum Member
davidt's Avatar

Join Date: Apr 2009
Location: Vienna
Posts: 50
Original Poster
Thanks for your quick replies!

QuoteQuote:
i can only imagine fungus getting in when the lens is unmounted - otherwise the seals are quite resistant to water. Sooooooo... either you didn't keep them dry enough or your lens sealing isn't working. Except you'd probably notice the sealing not working if you used them in the rain.
Yes of course they where not always mounted on the camera. So I understand they where exposed to high humidity.

QuoteQuote:
Take a tip from those of us who live in the tropics with very high humidity. Keep your gear in a dry case or a dehumidifier where the RH can be adjusted to about 40%. Using silica get is next to useless and don't forget it is easy for a camera bag to retain moisture.
But when travelling it's not possible to carry a dehumidifier or a box with a bulb with you. Especially when you try to keep your luggage as light as possible.

QuoteQuote:
Also, about your silica gel packets - are you certain they were dry?
Yes whenever I've checked them they where absolutely dry. So I was wondering if they are working at all.

QuoteQuote:
Bath them in strong UV light.
This does only work to prevent fungus - it doesn't let it disappear, doesn't it?

So it would be great if you could tell me if a camera repair center could heal them at all. What I read was that most lens companies don't offer such a service themselves. So I must rely on a 3rd party repair center. But I'm afraid they won't be able to deal with a WR lens and the mentioned collimation. And the expected price...

02-26-2012, 08:21 PM - 1 Like   #9
Veteran Member
Docrwm's Avatar

Join Date: Sep 2010
Location: Somewhere in the Southern US
Photos: Gallery | Albums
Posts: 11,275
You really can't tell by touch if a silica packet is "completely dry". You can either bake them at a low even temp in an oven to eliminate molisture or get new ones that are sealed. In either case, they only work for a brief period. Also, the type of case can contribute to additional moisture as most modern cases have lots of dense foam padding that can be a great source for moisture.
02-26-2012, 08:37 PM   #10
Forum Member




Join Date: Feb 2012
Location: Philadelphia
Posts: 88
I don't often say this.... but I think I'd listen to Creampuff.
02-26-2012, 11:22 PM   #11
Pentaxian
philbaum's Avatar

Join Date: Oct 2007
Location: Port Townsend, Washington State, USA
Posts: 3,659
I had black fungus on the underside of my house roof. I called in an expert who tested the wood for moisture content. I'm not too sure about the numbers, but i think he said that the fungus was dormant because the moisture was below 20% or some such number. You can't eliminate spores entirely because they are everywhere in normal environments, the key is to keep the humidity below the dormant level. As the moisture reaches the critical number, it starts growing again.

Creampuff's advice sounds right. In the Pacific Northwest, i heard a lecture from a pro who used selica packets in his camera bag, but he frequently dried them out in an oven. The problem with that is how does one ever know how dry the material is and how often one should dry them out. But humid environments like yours are an entirely different kettle of problems,i would imagine.

best of luck.
02-27-2012, 06:10 AM   #12
Forum Member
davidt's Avatar

Join Date: Apr 2009
Location: Vienna
Posts: 50
Original Poster
Well I met locals which used a cabinet with a light-bulb to keep their electronics dry and safe. In India you often have to be happy if you have even electricity. The worst thing I have experienced was a one week power-cut due to a cyclone. At that time it was raining heavily, going out of the house was highly dangerous because of falling trees. And the air was so humid that all clothes inside the house where soaked with water. When opening my MacBook there was mist all over the display. Luckily it survived. As soon the sun came back of course I was drying all my stuff. So in such cases silica gel packages are quite useless - when everything is wet. A friend had these Pelican boxes - but they are big and bulky and you cannot just put them in your backbag. It is clear to me that these where not the best circumstances to prevent fungus.

I'd love to know what i can do -now- to save my beloved DA* 50-135mm.
02-27-2012, 06:18 AM   #13
Forum Member
davidt's Avatar

Join Date: Apr 2009
Location: Vienna
Posts: 50
Original Poster
QuoteOriginally posted by Docrwm Quote
Also, the type of case can contribute to additional moisture as most modern cases have lots of dense foam padding that can be a great source for moisture.
Yes my Tamrac backbag has lot's of these paddings. Hence it seems contraproductive to store your stuff in such a bag.
02-27-2012, 06:59 AM   #14
Veteran Member
Reportage's Avatar

Join Date: Feb 2009
Photos: Gallery
Posts: 739
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.
02-27-2012, 07:47 AM   #15
Pentaxian
philbaum's Avatar

Join Date: Oct 2007
Location: Port Townsend, Washington State, USA
Posts: 3,659
QuoteOriginally posted by davidt Quote
Well I met locals which used a cabinet with a light-bulb to keep their electronics dry and safe. In India you often have to be happy if you have even electricity. The worst thing I have experienced was a one week power-cut due to a cyclone. At that time it was raining heavily, going out of the house was highly dangerous because of falling trees. And the air was so humid that all clothes inside the house where soaked with water. When opening my MacBook there was mist all over the display. Luckily it survived. As soon the sun came back of course I was drying all my stuff. So in such cases silica gel packages are quite useless - when everything is wet. A friend had these Pelican boxes - but they are big and bulky and you cannot just put them in your backbag. It is clear to me that these where not the best circumstances to prevent fungus.

I'd love to know what i can do -now- to save my beloved DA* 50-135mm.
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.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
16-50mm, 50-135mm, da*, da* 16-50mm, fungus, k-mount, lenses, pentax, pentax lens, slr lens, time, wr
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
How to Remove Fungus: A 50mm F1.7 lens adr1an Do-It-Yourself 14 08-30-2012 04:04 AM
For Sale - Sold: K7, FA-77mm, FA-50mm, Da 18-135mm & DA 55-300mm Ed n Georgia Sold Items 5 03-28-2011 03:34 AM
For Sale - Sold: K20D <1800 Shutter Count, DA* 16-50mm, DA* 50-135mm, DA* 200mm, FA 50mm f1.4 ( Andy Compton Sold Items 8 07-10-2010 06:44 AM
For Sale - Sold: Super Takumar 135mm & 200mm, Vivitar 135mm, SMC 28mm MSM Sold Items 24 06-13-2010 09:55 PM
For Sale - Sold: Pentax 50mm macro, 28mm & 135mm roro Sold Items 5 01-29-2009 09:30 PM



All times are GMT -7. The time now is 07:19 PM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top