topic Lens Fungus Prevention Best Practices in EF & RF Lenses

Lens Fungus Prevention Best Practices

danimal59 — Tue, 09 May 2023 13:21:44 GMT

Good Morning,

I recently purchased a T7 kit as well as two additional lenses. I live in Western Pennsylvania and store my equipment in a LowePro bag.

The other night in the Canon Community I came across some posts about lens fungus and I have been trying to educate myself about what I should be doing to best protect my equipment.

Specifically I have read about people storing their lenses in plastic bags with silica gel packs and some going as far as purchasing Ruggard humidity controlled dry cabinets.

I wanted to see if members here may have some suggestions so that I can find the best solution for my needs.

Thank you,

Dan

Re: Lens Fungus Prevention Best Practices

ebiggs1 — Wed, 10 May 2023 14:53:38 GMT

I have been doing photography from the tintype age to now. I do nothing extra special and have never had any fungus problem. Fungus likes dark moist areas so don't do that. Most of my gear is stored on plain open shelves in my formerly stop bath stained dark room converted to storage room.

I am not saying this to be rude or condescending but consider the value of a Rebel T7 kit and the cost of replacement vs the cost of any extraordinary fungus reduction method or methods. I have a dehumidifier in there because I do have a great deal of equipment stored there. A little cost analysis is a good thing.

Re: Lens Fungus Prevention Best Practices

danimal59 — Tue, 09 May 2023 14:28:09 GMT

I have followed your posts for sometime and I am not surprised you said this about my equipment. Just FYI I find your comment to be condescending. Just because the equipment may not be meaningful to you I already bought two more lenses and you didn’t ask if I was planning to buy more.

Dan

Re: Lens Fungus Prevention Best Practices

wq9nsc — Tue, 09 May 2023 14:44:19 GMT

I don't do anything too special with my lenses. I do shoot a lot of sports and if the equipment is damp it gets wiped down with a dry cloth and allowed to sit in an open area for a day before going back into my storage room. I keep desiccant packs around and use those at times in the lens suitcases that come with the Canon "great white" primes. Desiccant packs are reusable and "baking" at a very low temperature (not over 150 degrees) for a couple of hours will restore them by removing moisture. I use mil spec packs that change color to indicate when they need to be baked but you can just use the regular packs that come with most consumer electronics gear these days.

Fungus isn't going to form unless the lens is stored in a damp and dark location for a longer period of time. So don't put your gear away damp in a sealed or semi-sealed container, make sure the storage area doesn't have a sustained high humidity level, and use extra caution if you live in a high humidity area where the gear is frequently staying in high humidity because this is what causes fungus growth.

I have used Canon SLR and later DSLR cameras since the late 1970s and I bought my first Canon SLR cameras and lenses when I was living on the Mississippi gulf coast less than a mile from the water. I never took any special precautions and I have never had any fungus issues. Bottom line is, it can happen but speaking from the point of view of someone who spent most of his career doing enterprise risk management: There are a lot more likely bad things that will happen to your camera gear so don't over-stress about the possibility of fungal buildup.

Rodger

Re: Lens Fungus Prevention Best Practices

krahe — Tue, 09 May 2023 20:07:53 GMT

I've been concerned about this ever since I saw used lenses out there with the problem. What I do if I've been out shooting in a humid area is when I get to someplace dry (and clean!), like an air conditioned room, I will exercise the lenses I had been using, such as by zooming them in and out a few times (for zoom lenses) and/or exercising the focus mechanism, with the lens caps off, too, of course. My thinking is that this will displace any moist air left in the lens with drier ambient air.

Re: Lens Fungus Prevention Best Practices

AtticusLake — Wed, 10 May 2023 06:47:35 GMT

I'm sorry you found EB's post condescending. It didn't strike me that way; he seems to be giving good advice, and it didn't look like he was making unwarranted assumptions about your gear.

Fungus seems like a pretty low risk to me -- I certainly haven't come across it in 23 years of owning ILCs -- and compared to the cost of a dry cabinet, the T7 is not a high-cost item. I'm seeing it on sale for under £420 with lens (the Rebel 2000D here in the UK). Of course only you know how much you've spent on additional lenses.

EB is simply pointing out that if a person happens to have, let's say, £900 worth of lenses, and they spend £1000 on a cabinet to protect them from fungus, then they might want to reconsider. Even less drastic protection methods might not be worth it, given that fungus issues are not common. Of course, if you live in a swamp, it might be different.

Personally, I have an R5C, a C70, and four RF-mount lenses. I keep my lenses on the bottom shelf of the coffee table. Dust is my only concern. If they get damp, I let them sit on the table and breathe with the caps off etc.

Re: Lens Fungus Prevention Best Practices

shadowsports — Wed, 10 May 2023 14:25:21 GMT

Wiping stuff down, keeping it clean and dry is my recipe for success. I live in Nor Cal, 1 mile from the ocean. Old house, not so weather sealed and no dehumidification. I've done insulation and windows, but our coastal area is often foggy, misty and moist. We do have a portable dehumidifier in a downstairs bedroom. It fills up rapidly. When we replace our furnaces, we plan to install a dehumidification system as well. Clean and dry are the most important things. I didn't think @Ernies comments were condescending at all. He was just pointing out considerations when deciding how to protect an investment.

Re: Lens Fungus Prevention Best Practices

normadel — Thu, 11 May 2023 15:54:45 GMT

You never know how used lenses were kept/stored. They could have been stashed away in a musty, moldy basement for many years. They could have been through a flood. I've seen a LOT of this while working at a reuse-recycling business. We get camera donations that actually SMELL like mildew and show it externally. Wiping down a lens or camera with alcohol or whatever does nothing to what's inside of it.

Re: Lens Fungus Prevention Best Practices

Tronhard — Fri, 12 May 2023 04:10:59 GMT

Really, much depends on your environment, by which I mean both the ambient condition outside and the design and structure of your house inside. For example: I live in Auckland, New Zealand and it gets pretty muggy in the summer. I am not familiar with conditions in Pennsylvania, so apologies for not being familiar with your environment.

For some years I lived in a house with single-pane glass and fairly minimal insulation. In winter the windows would fog up and we would get mold on some surfaces, especially in places open to moisture, like the bathroom and kitchen, or the lounge - which was off the kitchen.

My solution at that time was to keep the lenses in their original packaging (which is also great for resale as it attracts confidence and often gets a better price), along with mini silica gel packets in the boxes, plus larger dehumidifying packets on each shelf, and the cupboard had two outside walls and thus did not get too much exposure to inside air. I always kept the door to that cupboard closed when not actually accessing my gear.

When out shooting, I avoided rain and kept my cameras in holsters when not in use. On the few occasions I have shot in very cold conditions, I have put the camera and lens in a plastic bag when returning indoors while they warm up and have had no issues. Finally, I never change lenses in the field so each lens has its own body - which is my choice, as I want to avoid moisture and dirt getting into the camera body and I often need to change focal lengths very quickly.

Some years back we moved into a much more modern house, with significant insulation, double-glazing, heat pumps and a dehumidifying system. I never get condensation inside but I still protect my gear as before. I have never had fungus in a lens in my years of shooting.

My gear has included from the top end pro gear that is weather sealed to the more consumer units - so what you would call Rebels, and kit lenses, so I am not talking about high-end stuff that is very expensive.

I hope this is of some assistance.

Re: Lens Fungus Prevention Best Practices

ebiggs1 — Fri, 12 May 2023 14:52:30 GMT

"My solution ... was to keep the lenses in their original packaging (which is also great for resale as it attracts confidence and often gets a better price), along with mini silica gel packets in the boxes, plus larger dehumidifying packets on each shelf .... I avoided rain and kept my cameras in holsters when not in use.... I have put the camera and lens in a plastic bag when returning indoors while they warm up ... I never change lenses in the field ... I want to avoid moisture and dirt getting into the camera body ... "

I never do or did any of that. I shoot when I want to and where I want to in whatever conditions that exists. I even did a shoot for a client that involved shooting during hurricane Ivan. My motto is if the conditions are too bad for me they are too bad for my gear. Ivan pushed the limits for sure. If you camera gear doesn't do what you want or you are afraid to use it, it is of little use.

"... keep the lenses in their original packaging (which is also great for resale as it attracts confidence and often gets a better price)..."

I bet the next guy appreciates you for that. I admit I did the very same thing while I was in my lens testing phase. It was fun at the time but thank heaven that's over!

Re: Lens Fungus Prevention Best Practices

Tronhard — Fri, 12 May 2023 18:42:52 GMT

As I understand it, the issue was more about how the lenses should be stored rather than how they are used in the field, although, to be thorough, I covered both to a degree.

If one lives in a house that is prone to moisture and the elements, then there could be concerns. That said, if it's that likely to impact the lenses with fungus, it's not likely to be good for human habitation - something that has been an issue in NZ where houses were, for a long time, very poorly insulated and many in lower socio-economic areas still are. I know when we moved to the current house, with it's very much improved environment, the occurrence of colds and other cardio-respiratory issues dropped to almost zero.

Re: Lens Fungus Prevention Best Practices

ebiggs1 — Sat, 13 May 2023 19:37:00 GMT

"That said, if it's that likely to impact the lenses with fungus, it's not likely to be good for human habitation ..."

Good point, Trevor. 😮

"... the issue was more about how the lenses should be stored rather than how they are used ..."

However, how the gear is used dictates how it should be handled as one puts it away. Even if it is just a quick wipe down with a micro fiber cloth. It is important and I know camera is not cheap, but keep it in perspective. It is only a lens. Use it, enjoy it and don't fret or worry over it, to much. Reasonable care will suffice in most situations.

I know the OP didn't like my first advice but its not logical to spend a lot of money on preventive measures for something that can be replaced so readily if the worst happens.

Re: Lens Fungus Prevention Best Practices

Tronhard — Sat, 13 May 2023 19:48:12 GMT

In NZ we have a legacy of leaky and poorly insulated homes - it was really only until about the end of the last century that double-glazing and comprehensive insulation were mandatory. Now heat pumps are required on all rentals and new builds as well.

I fully accept that I am very conservative in my care of my gear, and have clearly said so, but I was brought up with the motto "take care of your gear and it will take care of you". Doing so does not, in any way diminish my enjoyment of actually using it - it it's pouring with rain, I'm not going to be comfortable in it any more than the camera will. 🙂

As always there is a spectrum of views on the subject, but at least the OP is getting a range of opinions and that is good.

Re: Lens Fungus Prevention Best Practices

Doormat — Mon, 19 Jan 2026 17:19:06 GMT

All my lenses

EF, EF-S, EF-M, RF & RF-s are all kept inside large clear plastic boxes (with lids) each box contain multiple giant sachets of silica gel.

i read that storing gear in camera bags was actually the worst possible idea. Hence everything of mine including bodies and flashes are all stored loosely in the same way as my lenses.

Re: Lens Fungus Prevention Best Practices

shadowsports — Mon, 19 Jan 2026 22:20:31 GMT

Over a year ago, maybe two, I purchased a Ruggard dry cabinet from B&H. Maintains temperature and humidity at whatever level you set.

Everyone has their own methods and opinions on how to store their gear, but I have to say that the dry cabinet has been set and forget for me.

Mold and fungus can't grow in unfavorable conditions. Dry cabinets are not affected by external environment. There's no silica gel packs to mess with or anything you have to watch or remember to change.

It wasn't expensive and does exactly what I wanted. Climate control works for a reason. So my advice is do whatever works for you.

Re: Lens Fungus Prevention Best Practices

ebiggs1 — Tue, 20 Jan 2026 15:21:52 GMT

"There's no silica gel packs to mess with or anything you have to watch or remember to change."

Most people forget silica gel 'wears' out or fills up if you will. It is not a toss it in and forget it. Also they have no idea how much or how big a pack you really need to have any effect at all. It is a lot more than you may think.

Re: Lens Fungus Prevention Best Practices

justadude — Wed, 28 Jan 2026 15:30:54 GMT

"i read that storing gear in camera bags was actually the worst possible idea."

I've heard that too, but I've been keeping my gear in various bags with silica gel packets for as long as I can remember, probably close to 50 years with the silica gel. I live in Michigan close to the Great Lakes, so the air gets very humid in the summer and often in the winter and spring. Fall seems to be less humid. My wife and I don't like air conditioning (prefer the fresh warm and humid air), so our house is often on the humid side. Anyway, almost all of my gear (current count is 33 cameras of all types, and a few dozen lenses) is almost always stored in the various bags after use, other than a few old ones I keep on a display shelf. Some of the digital gear I shoot in rainy conditions, but dry it off before putting it back in the bag (same day as it was used). The film gear rarely gets used in the rain, but it does happen. Never once had a problem with this worst idea, but that's just me maybe? I've talked about this before with local photographer friends. I know one guy who has a dehumidifying case, but the others do similar to what I do about keeping them in a bag (but not all use silica gel).

The difference might be because I rotate the silica gel out roughly every six months? I keep a half dozen in each case or bag. Maybe these first 50 years I've been lucky. Ask me again in another 50, and I may have a different answer.

Bottom line, I think you might be overly concerned.

Re: Lens Fungus Prevention Best Practices

justadude — Wed, 28 Jan 2026 15:33:44 GMT

"Also they have no idea how much or how big a pack you really need to have any effect at all. It is a lot more than you may think."

Personally I've had good luck scattering a half dozen packets in each bag, then changing them out every six months (sooner in the summer). It's not an exact science at all, but it's been working for decades for me.

Re: Lens Fungus Prevention Best Practices

ebiggs1 — Wed, 28 Jan 2026 16:36:34 GMT

Causation vs correlation my friend. It means the fact it has or apparently has worked to a satisfactory result for you is not proof it works as a certainty. If you opened the bag at any time in that six month cycle you probably ruined the silica gel packs. As long as the bag remained sealed they would probably be good. Personally I do not do any extraordinary measures and have not seen any fungus. My darkroom/storage room does have a dehumidifier as does my music room. Most of my gear is in camera bags, too.

Kansas is pretty dry during the winter but humidity can soar to well into the 90+% range during the summer.