[672]

Well, Of course it hits the 67 75mm 2.8 AL, and not the 135 macro sitting right next to it...... So, I have about 25 lenses from Pentax and Canon locked up in a steel multi drawer tool chest in my home office. Been that way for twelve years . I use piles of desiccant packs , big 400 gram ones. Everything was fine when I bought new ones regularly , but recently I have been "drying" them out in the oven. Maybe back to new ones all the time. Basically Im looking for feedback and experience on how to improve my long term storage.

Best, 672

[TDvN57]

Well, Of course it hits the 67 75mm 2.8 AL, and not the 135 macro sitting right next to it...... So, I have about 25 lenses from Pentax and Canon locked up in a steel multi drawer tool chest in my home office. Been that way for twelve years . I use piles of desiccant packs , big 400 gram ones. Everything was fine when I bought new ones regularly , but recently I have been "drying" them out in the oven. Maybe back to new ones all the time. Basically Im looking for feedback and experience on how to improve my long term storage.

Best, 672

Fungus on a lens a bummer. Is bad news anywhere unless it is part of a meal.

I use a dry box (cabinet) which may be a bit more consistent in keeping the humidity down. About twice a year a put the lenses in the sun with the glass facing at the sun, for about an hour, whilst watching that the lenses don't heat up beyond normal usage temperature.

The idea is not to heat up the lens, because that may cause lubricants to migrate and other potential damage, but the idea is to get UV onto the glass. The better option will probably be to use a UV light, but I reckon the sun is free and strong enough, done with caution of course.

If the fungus just started you can try to kill it with sunlight (UV), but it won't remove the stain. I think baking in an oven won't be hot enough to kill fungus and may cause other damage.

[672]

great stuff, I'll look into the artificial light angle as well......... thanks!

[Stefan Jr]

The idea is not to heat up the lens, because that may cause lubricants to migrate and other potential damage, but the idea is to get UV onto the glass. The better option will probably be to use a UV light, but I reckon the sun is free and strong enough, done with caution of course.

Correct me if I'm wrong.

It's UV-C that penetrates the glass and kills the fungus.

While UV-B and UV-A will have no effect. Firstly - because it does not penetrate glass. And secondly - it has no sterilizing effect.

So, if anyone trying to treat/disinfect a lens with a lamp. Make sure it's an UV-C sterilizing lamp!

---

Last edited by Stefan Jr; 01-06-2023 at 11:41 PM.

[catfishjohn]

You can purchase low temperature automatic heaters for your cabinets. Just search "gun safe heater dehumidifier " they come in different lengths, plug into a wall outlet and stay just barely warm to the touch. Maintains air temperature just enough to keep humidity at bay. Plug in and forget, no more buying and changing desiccant packs.

[tryphon4]

I always store my lenses in transparent airtight closed plastic boxes with silica (or absorbent clays) and an hygrometer.
As I found difficult to regenerate the absorber in an oven, I recently bought a dry cabinet where I store each box in order to dry both lenses and absorber. After a few days (when the humidity reaches 35%HR) , I close the box and replace it by another one in the cabinet.
My closed boxes are stored in a bright place.

[ramseybuckeye]

You can purchase low temperature automatic heaters for your cabinets. Just search "gun safe heater dehumidifier " they come in different lengths, plug into a wall outlet and stay just barely warm to the touch. Maintains air temperature just enough to keep humidity at bay. Plug in and forget, no more buying and changing desiccant packs.

This is an excellent idea, I would guess that is what is built into a dry cabinet. I have a dry cabinet, but if I had another container for storage that would be an easy conversion.

[catfishjohn]

I bought a low wattage 110v UV light off Ebay. Used to rid Takumar lens of yellow discoloration due to radioactive elements. Worked great and another advantage is that it also kills fungus. I went ahead and gave my modern lenses a dose to rid them of any spores. If a lens has dust inside it likely has dormant spores. The lights don't heat the lens as does sun exposure and works fast. Putting a mirror or foil behind the lens will reflect the light back thru and speed the process. Place the light a few inches from the light as it does generate a little heat. Also be aware that the light will cause some minor sunburn and eye discomfort with surprisingly short exposure. I would recommend wearing sunglasses. I am sure it kills spores quickly because of the sunburn effect I experienced. Do the treatment somewhere others will not be unwittingly exposed or place a box over.

[Bob 256]

Correct me if I'm wrong.

It's UV-C that penetrates the glass and kills the fungus.

While UV-B and UV-A will have no effect. Firstly - because it does not penetrate glass. And secondly - it has no sterilizing effect.

So, if anyone trying to treat/disinfect a lens with a lamp. Make sure it's an UV-C sterilizing lamp!

UC-C (UV below 290nm) won't penetrate glass much at all (unless the glass is an exotic one like quartz or fluorite). It's mostly UV-A and B that get in and UV-B does most of the work. Unfortunately, it's a probability thing and unless you kill 100% of the fungus, it will start to grow again when conditions are right. Killing 100% with UV is hard to do and you always have cracks and crevices where the light won't get to. Worth a shot but not the same as disassembly and germicidal treatment. Best not to get an infection to begin with.

[Stefan Jr]

UC-C (UV below 290nm) won't penetrate glass much at all (unless the glass is an exotic one like quartz or fluorite). It's mostly UV-A and B that get in and UV-B does most of the work. Unfortunately, it's a probability thing and unless you kill 100% of the fungus, it will start to grow again when conditions are right. Killing 100% with UV is hard to do and you always have cracks and crevices where the light won't get to. Worth a shot but not the same as disassembly and germicidal treatment. Best not to get an infection to begin with.

Well - it's mainly UV-C that is used for sterilizing/disinfecting purposes.

UV-B is to a large extent beneficial to life, and most is blocked by glass (every herpetologist know that).
But maybe UV-A could have some effect on fungus? I don't know.

If I would try any lamp - it would certainly be some sort of UV-C sterilizing lamp.
Combined with a partial disassembly of the lens, to optimize the effect, is probably not a bad idea.

(But, yes, it's certainly best not to spawn an infection to start with. Fully agree with that).

[yucatanPentax]

The steel tool cabinet is not sealed, so more humidity likely gets in than desiccants can absorb. Think of water vapor in the air as like liquid water -- it gets in everywhere that's not sealed off.

Maybe a dry cabinet, transparent plastic boxes that seal well with desiccants, or dry boxes with desiccants. None are as convenient as having everything in a conveniently opening slide drawer though.

[barondla]

Silica gel is some of the last effective desiccant. It rapidly looses absorption efficiency around 100 F. This makes it almost useless in tropical climates. Here is a list of desiccants and their abilities.
Top 6 Desiccant Types to Prevent Moisture Damage - Lab Supply Network.

WARNING: UV B & especially C are very dangerous to humans. With C appropriately rated goggles must be worn. Permanent eye damage starts after only a few minutes without protection. Clothing, including gloves, should be heavy cotton. Many many man made fabrics allow UV C to pass straight through. More info can be found by searching the web. Ultraviolet Photographydotcom is a good source. They won't even allow posts about UV C without a warning. It is that serious. Even low output C lamps are more potent than sunlight. Be careful.

Thanks
barondla

[672]

thanks everyone ! all great info . much needed to get me back on track.

[yucatanPentax]

Silica gel is some of the last effective desiccant. It rapidly looses absorption efficiency around 100 F. This makes it almost useless in tropical climates. Here is a list of desiccants and their abilities.
Top 6 Desiccant Types to Prevent Moisture Damage - Lab Supply Network.

Looking at that list of six, which would you use or do you use for desiccant purposes with cameras and lenses? Some seem a little exotic. Maybe that's why silica gel is more common?

[TheSwede]

I this a tropics thing or does it happen all over the globe? I see that one of you is from Berlin. That does not sound very tropic to me. I am stationed i south of Sweden.