Fungus (?) inside RF 70-200 F4 L

Started 3 months ago | Discussions
Sinawang Forum Member • Posts: 67
Fungus (?) inside RF 70-200 F4 L

I found this yesterday morning. Knowing that this lens is sealed and pro grade, but when I find something like this, sure I'm disappointed.

This is the lens which attached on the camera more than my other lenses.

The spot is near the upper-right edge on the backside of the front element, so it's not seen in the frame, I guess because it's outside of the coverage area of the sensor.

How to save this lens from the fungus (?) spread further if this already happened?

What cost me if I send it to service centre to clean?

 Sinawang's gear list:Sinawang's gear list
Canon EOS RP Canon EF 16-35mm F4L IS USM Canon 85mm F1.4L IS USM Canon RF 50mm F1.8 STM Canon RF 70-200 F4 L +1 more
Dan W Contributing Member • Posts: 834
Re: Fungus (?) inside RF 70-200 F4 L

Sinawang wrote:

I found this yesterday morning. Knowing that this lens is sealed and pro grade, but when I find something like this, sure I'm disappointed.

This is the lens which attached on the camera more than my other lenses.

The spot is near the upper-right edge on the backside of the front element, so it's not seen in the frame, I guess because it's outside of the coverage area of the sensor.

How to save this lens from the fungus (?) spread further if this already happened?

What cost me if I send it to service centre to clean?

Might be under warranty. Worth a call. Do you live in a humid climate like Florida or other southern state? They make drying cabinets that B&H sells. Or you can make one, just build a box and wire a 25 or 40 watt bulb (not LED bulb) like an appliance bulb. The heat from the bulb will keep humidity at bay, humidity is the enemy to lenses. The ones you buy look sorta like a dorm refrigerator with a glass door. Its just a mildly warm cabinet that keeps mold and fungus from taking off.

 Dan W's gear list:Dan W's gear list
Canon EOS R Canon EOS R5 Canon RF 50mm F1.2L USM Canon RF 35mm F1.8 IS STM Macro Canon RF 24-105mm F4L IS USM +1 more
OP Sinawang Forum Member • Posts: 67
Re: Fungus (?) inside RF 70-200 F4 L

Dan W wrote:

Might be under warranty. Worth a call. Do you live in a humid climate like Florida or other southern state? They make drying cabinets that B&H sells. Or you can make one, just build a box and wire a 25 or 40 watt bulb (not LED bulb) like an appliance bulb. The heat from the bulb will keep humidity at bay, humidity is the enemy to lenses. The ones you buy look sorta like a dorm refrigerator with a glass door. Its just a mildly warm cabinet that keeps mold and fungus from taking off.

The fact that this happened inside a sealed & pro-grade lens really disappoint me.

I put it with some silica gel around it.

I read some article mentioned that fungus is outside of warranty coverage. I'll confirm about this.

What if fungus is not covered by warranty?

Can the fungus disappear by only storing the lens inside dry box if the fungus is already there?

 Sinawang's gear list:Sinawang's gear list
Canon EOS RP Canon EF 16-35mm F4L IS USM Canon 85mm F1.4L IS USM Canon RF 50mm F1.8 STM Canon RF 70-200 F4 L +1 more
MannyV
MannyV Contributing Member • Posts: 907
Re: Fungus (?) inside RF 70-200 F4 L
2

Sinawang wrote:

Dan W wrote:

Might be under warranty. Worth a call. Do you live in a humid climate like Florida or other southern state? They make drying cabinets that B&H sells. Or you can make one, just build a box and wire a 25 or 40 watt bulb (not LED bulb) like an appliance bulb. The heat from the bulb will keep humidity at bay, humidity is the enemy to lenses. The ones you buy look sorta like a dorm refrigerator with a glass door. Its just a mildly warm cabinet that keeps mold and fungus from taking off.

The fact that this happened inside a sealed & pro-grade lens really disappoint me.

I put it with some silica gel around it.

I read some article mentioned that fungus is outside of warranty coverage. I'll confirm about this.

What if fungus is not covered by warranty?

Can the fungus disappear by only storing the lens inside dry box if the fungus is already there?

Ever move from aircon room to outside in a hot humid country? Ever noticed what happens to lens when you do that? Those who live in such environment know how this condensation occurs. Both inside and outside of lens and irrespective of weather sealed or not. Google how to avoid this in future. Also dry cabinets are a hot commodity in such places.

Not something new with lens. Any expensive stuff that can corrode, video tapes, etc would be stored in those cabinets when not in use. Wish you luck.

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Manny
Still draft and working towards it - https://www.digitalphoto.work

OP Sinawang Forum Member • Posts: 67
Re: Fungus (?) inside RF 70-200 F4 L

MannyV wrote:

Ever move from aircon room to outside in a hot humid country? Ever noticed what happens to lens when you do that? Those who live in such environment know how this condensation occurs. Both inside and outside of lens and irrespective of weather sealed or not. Google how to avoid this in future. Also dry cabinets are a hot commodity in such places.

The spot stays there after 24hr since I found it on the lens, it's not like condensation. I know about condensation, when the temps on both side inside & outside is equal, the fog will gone, but this one doesn't.

I check it from time to time to see if it spreads further radially, hopefully it won't grow any further.

Not something new with lens. Any expensive stuff that can corrode, video tapes, etc would be tried and stored in those cabinets when not in use. Wish you luck.

 Sinawang's gear list:Sinawang's gear list
Canon EOS RP Canon EF 16-35mm F4L IS USM Canon 85mm F1.4L IS USM Canon RF 50mm F1.8 STM Canon RF 70-200 F4 L +1 more
Dan W Contributing Member • Posts: 834
Re: Fungus (?) inside RF 70-200 F4 L

Sinawang wrote:

MannyV wrote:

Ever move from aircon room to outside in a hot humid country? Ever noticed what happens to lens when you do that? Those who live in such environment know how this condensation occurs. Both inside and outside of lens and irrespective of weather sealed or not. Google how to avoid this in future. Also dry cabinets are a hot commodity in such places.

The spot stays there after 24hr since I found it on the lens, it's not like condensation. I know about condensation, when the temps on both side inside & outside is equal, the fog will gone, but this one doesn't.

I check it from time to time to see if it spreads further radially, hopefully it won't grow any further.

Not something new with lens. Any expensive stuff that can corrode, video tapes, etc would be tried and stored in those cabinets when not in use. Wish you luck.

I dont know of any lens that is air tight and sealed that way. "Sealed" L lenses just means its seals out dust and a little rain, not dropped in a pond sealed. If you look at any doubled glazed windows sash over 20 years old, you will likely see the same thing in your lens, a fog that never goes away. Thats because the air tight seal has broken down over the years and is letting moisture in.

In the case of lenses, just humid climates and humid storage can cause this. Unfortunately this is not uncommon in some areas. Condensation may happen when you come out of a well air-conditioned home to a humid outdoors. But thats not what "HAS TOO" happen to get fungus and mold. I fight mold on the north side of my house because it never sees direct sunlight. Look on eBay and you will see modern day lenses as well as legacy lenses that will state in the listing that their lens is "Fungus Free". First thing I look for or ask when considering a second hand lens.

The good news is you can have it cleaned, bad news is it won't go away on its own. You need to make sure you dry out the lens very well in a dry cabinet or leave it out in the sun on hot dry days to kill off the fungus. at least that will stop it from growing worse. UV will kill fungus.

You may be right about not covered in the warranty, its not really a manufacturing defect. It's more an environmental issue that is out of Canon's control. But I would still make that call to canon and see what they say. won't cost you anything to call other then your time... Good luck...

 Dan W's gear list:Dan W's gear list
Canon EOS R Canon EOS R5 Canon RF 50mm F1.2L USM Canon RF 35mm F1.8 IS STM Macro Canon RF 24-105mm F4L IS USM +1 more
PicPocket Veteran Member • Posts: 4,853
Re: a few things about this

Sinawang wrote:

I found this yesterday morning.

First, let me start by saying, I'm not sure if this is fungus. Hard to make out conclusively from photo. But, I'll err on the side of assuming that it is fungus, because if it spreads, the lens is mostly done for

Knowing that this lens is sealed and pro grade, but when I find something like this, sure I'm disappointed.

No lens is sealed for fungus. Moisture can form inside lenses without crossing the seals, the air inside the lens isn't completely dry and the lens isn't airtight. Vapour is not the same as water droplets. Same goes for microorganisms that make up the fungi. Too small to seal against in a consumer device

How to save this lens from the fungus (?) spread further if this already happened?

First step is to make sure it's not alive. UV light is fungus killer. You need to make it spend a long time in sunlight or a good UV lamp. If it dies out, it will probably dust off. If even a spek of it remains, it will grow.

What cost me if I send it to service centre to clean?

Canon must have a fixed cleaning charge. Call them up

As for some of the posters mentioning dry cabinets, don't use the ones that heat up or use a bulb. The decent ones use a peltier device that suck condense out the moisture without raising the temperature inside. A hot cabinet isn't good for rubber etc on equipment in long run. I live in HK and the humidity here means everyone with some equipment uses one of those. It's simple and cheap and takes this worry completely away. Been using one for last 15 years (yes, they can last very long)

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 PicPocket's gear list:PicPocket's gear list
Canon EOS M50 Canon EOS R5 Canon EF 85mm F1.8 USM Tokina AT-X Pro 11-16mm f/2.8 DX Sigma 150mm F2.8 EX DG Macro HSM +15 more
OP Sinawang Forum Member • Posts: 67
Re: Fungus (?) inside RF 70-200 F4 L

Dan W wrote:

I dont know of any lens that is air tight and sealed that way. "Sealed" L lenses just means its seals out dust and a little rain, not dropped in a pond sealed. If you look at any doubled glazed windows sash over 20 years old, you will likely see the same thing in your lens, a fog that never goes away. Thats because the air tight seal has broken down over the years and is letting moisture in.

Yes, me too. I mean the sealings at least can prevent some dust particles to enter. I know the sealings will still allow air to enter for the lens to breath as it's zooming in and out, basic physics, but I'm expecting more from the multiple sealing in preventing dust particles to enter the barrel.

In my case, unfortunately the dust particle has fungus spores on it and I can see it grows around that dust on my lens as it sticks on the back of the front element.

In the case of lenses, just humid climates and humid storage can cause this. Unfortunately this is not uncommon in some areas. Condensation may happen when you come out of a well air-conditioned home to a humid outdoors. But thats not what "HAS TOO" happen to get fungus and mold. I fight mold on the north side of my house because it never sees direct sunlight. Look on eBay and you will see modern day lenses as well as legacy lenses that will state in the listing that their lens is "Fungus Free". First thing I look for or ask when considering a second hand lens.

The good news is you can have it cleaned, bad news is it won't go away on its own. You need to make sure you dry out the lens very well in a dry cabinet or leave it out in the sun on hot dry days to kill off the fungus. at least that will stop it from growing worse. UV will kill fungus.

You may be right about not covered in the warranty, its not really a manufacturing defect. It's more an environmental issue that is out of Canon's control. But I would still make that call to canon and see what they say. won't cost you anything to call other then your time... Good luck...

I gather all my silica gels I have and put it around my 70-200 while I look for compact dry cabinets.

Yes Canon doesn't cover lens from fungus under warranty. That's too bad as it translates how the lens sealings integrity which is part of the lens manufacturing.

 Sinawang's gear list:Sinawang's gear list
Canon EOS RP Canon EF 16-35mm F4L IS USM Canon 85mm F1.4L IS USM Canon RF 50mm F1.8 STM Canon RF 70-200 F4 L +1 more
Dan W Contributing Member • Posts: 834
Re: Fungus (?) inside RF 70-200 F4 L

Sinawang wrote:

Dan W wrote:

I dont know of any lens that is air tight and sealed that way. "Sealed" L lenses just means its seals out dust and a little rain, not dropped in a pond sealed. If you look at any doubled glazed windows sash over 20 years old, you will likely see the same thing in your lens, a fog that never goes away. Thats because the air tight seal has broken down over the years and is letting moisture in.

Yes, me too. I mean the sealings at least can prevent some dust particles to enter. I know the sealings will still allow air to enter for the lens to breath as it's zooming in and out, basics physics, but I'm expecting more from the multiple sealing in preventing dust particles to enter the barrel.

In my case, unfortunately the dust particle has fungus spores on it and I can see it grows around that dust on my lens as it sticks on the back of the front element.

In the case of lenses, just humid climates and humid storage can cause this. Unfortunately this is not uncommon in some areas. Condensation may happen when you come out of a well air-conditioned home to a humid outdoors. But thats not what "HAS TOO" happen to get fungus and mold. I fight mold on the north side of my house because it never sees direct sunlight. Look on eBay and you will see modern day lenses as well as legacy lenses that will state in the listing that their lens is "Fungus Free". First thing I look for or ask when considering a second hand lens.

The good news is you can have it cleaned, bad news is it won't go away on its own. You need to make sure you dry out the lens very well in a dry cabinet or leave it out in the sun on hot dry days to kill off the fungus. at least that will stop it from growing worse. UV will kill fungus.

You may be right about not covered in the warranty, its not really a manufacturing defect. It's more an environmental issue that is out of Canon's control. But I would still make that call to canon and see what they say. won't cost you anything to call other then your time... Good luck...

I gather all my silica gels I have and put it around my 70-200 while I look for compact dry cabinets.

How old are your silica gels? they dont last that long once they absorb all the water it can.

Yes Canon doesn't cover lens from fungus under warranty. That's too bad as it translates how the lens sealings integrity which is part of the lens manufacturing.

Again its not a "Air Tight seal" and never claimed to be. May I ask what part of the country do you live? I'm in Ohio, Ohio summers can be pretty brutal but we go most of the summer in the air-conditioning. Some days its humid and some its just hot and dry. I personally never had a fungus issue even though I have had condensation inside the lens after walking out to the air into hot 80%+ RH.

But its important to kill the fungus to stop it from growing and spreading to even other lenses on your bag. UV lights are cheap and maybe let it set in front of one for a few weeks when not in use with the caps off and shinning into the lens.

I understand your frustration though. I really wish you the best here. Please at least talk to canon about this, if its not too old (that lens hasn't been out too long) then they may still take care of you even if its not covered. Be nice and pleasant on the phone and see what they do for you. I've gotten upgraded for free to 1st class for nothing more then asking and being pleasant.

 Dan W's gear list:Dan W's gear list
Canon EOS R Canon EOS R5 Canon RF 50mm F1.2L USM Canon RF 35mm F1.8 IS STM Macro Canon RF 24-105mm F4L IS USM +1 more
OP Sinawang Forum Member • Posts: 67
Re: a few things about this

PicPocket wrote:

Sinawang wrote:

I found this yesterday morning.

First, let me start by saying, I'm not sure if this is fungus. Hard to make out conclusively from photo. But, I'll err on the side of assuming that it is fungus, because if it spreads, the lens is mostly done for

Knowing that this lens is sealed and pro grade, but when I find something like this, sure I'm disappointed.

No lens is sealed for fungus. Moisture can form inside lenses without crossing the seals, the air inside the lens isn't completely dry and the lens isn't airtight. Vapour is not the same as water droplets. Same goes for microorganisms that make up the fungi. Too small to seal against in a consumer device

How to save this lens from the fungus (?) spread further if this already happened?

First step is to make sure it's not alive. UV light is fungus killer. You need to make it spend a long time in sunlight or a good UV lamp. If it dies out, it will probably dust off. If even a spek of it remains, it will grow.

What cost me if I send it to service centre to clean?

Canon must have a fixed cleaning charge. Call them up

As for some of the posters mentioning dry cabinets, don't use the ones that heat up or use a bulb. The decent ones use a peltier device that suck condense out the moisture without raising the temperature inside. A hot cabinet isn't good for rubber etc on equipment in long run. I live in HK and the humidity here means everyone with some equipment uses one of those. It's simple and cheap and takes this worry completely away. Been using one for last 15 years (yes, they can last very long)

Could you please recommend us one good compact dry cabinet for 1 camera, and 5 lenses under $500?

-- hide signature --
 Sinawang's gear list:Sinawang's gear list
Canon EOS RP Canon EF 16-35mm F4L IS USM Canon 85mm F1.4L IS USM Canon RF 50mm F1.8 STM Canon RF 70-200 F4 L +1 more
Dan W Contributing Member • Posts: 834
Re: a few things about this
1

Sinawang wrote:

PicPocket wrote:

Sinawang wrote:

I found this yesterday morning.

First, let me start by saying, I'm not sure if this is fungus. Hard to make out conclusively from photo. But, I'll err on the side of assuming that it is fungus, because if it spreads, the lens is mostly done for

Knowing that this lens is sealed and pro grade, but when I find something like this, sure I'm disappointed.

No lens is sealed for fungus. Moisture can form inside lenses without crossing the seals, the air inside the lens isn't completely dry and the lens isn't airtight. Vapour is not the same as water droplets. Same goes for microorganisms that make up the fungi. Too small to seal against in a consumer device

How to save this lens from the fungus (?) spread further if this already happened?

First step is to make sure it's not alive. UV light is fungus killer. You need to make it spend a long time in sunlight or a good UV lamp. If it dies out, it will probably dust off. If even a spek of it remains, it will grow.

What cost me if I send it to service centre to clean?

Canon must have a fixed cleaning charge. Call them up

As for some of the posters mentioning dry cabinets, don't use the ones that heat up or use a bulb. The decent ones use a peltier device that suck condense out the moisture without raising the temperature inside. A hot cabinet isn't good for rubber etc on equipment in long run. I live in HK and the humidity here means everyone with some equipment uses one of those. It's simple and cheap and takes this worry completely away. Been using one for last 15 years (yes, they can last very long)

Could you please recommend us one good compact dry cabinet for 1 camera, and 5 lenses under $500?

how bout this?

https://www.bhphotovideo.com/c/product/1282132-REG/ruggard_edc_80l_electronic_dry_cabinet_80l.html

 Dan W's gear list:Dan W's gear list
Canon EOS R Canon EOS R5 Canon RF 50mm F1.2L USM Canon RF 35mm F1.8 IS STM Macro Canon RF 24-105mm F4L IS USM +1 more
OP Sinawang Forum Member • Posts: 67
Re: Fungus (?) inside RF 70-200 F4 L

Dan W wrote:

I gather all my silica gels I have and put it around my 70-200 while I look for compact dry cabinets.

How old are your silica gels? they dont last that long once they absorb all the water it can.

Yes Canon doesn't cover lens from fungus under warranty. That's too bad as it translates how the lens sealings integrity which is part of the lens manufacturing.

Again its not a "Air Tight seal" and never claimed to be. May I ask what part of the country do you live? I'm in Ohio, Ohio summers can be pretty brutal but we go most of the summer in the air-conditioning. Some days its humid and some its just hot and dry. I personally never had a fungus issue even though I have had condensation inside the lens after walking out to the air into hot 80%+ RH.

But its important to kill the fungus to stop it from growing and spreading to even other lenses on your bag. UV lights are cheap and maybe let it set in front of one for a few weeks when not in use with the caps off and shinning into the lens.

I understand your frustration though. I really wish you the best here. Please at least talk to canon about this, if its not too old (that lens hasn't been out too long) then they may still take care of you even if its not covered. Be nice and pleasant on the phone and see what they do for you. I've gotten upgraded for free to 1st class for nothing more then asking and being pleasant.

I'm not sure of how old my silica gels are, but I'm restocking myself, and now I'm looking for portable UV light and compact dry cabinet. Never thought I will truly need all of these. I used to only put some silica gel sachets in my camera bags. I live in Asia.

What I'm asking is not about if the seals are air tight or not, but the integrity of the seal from preventing dust particles which are relatively bigger than air particles, where fungus spores might sticks on that dust particles, hope that make sense for Canon to understand this issue.

 Sinawang's gear list:Sinawang's gear list
Canon EOS RP Canon EF 16-35mm F4L IS USM Canon 85mm F1.4L IS USM Canon RF 50mm F1.8 STM Canon RF 70-200 F4 L +1 more
OP Sinawang Forum Member • Posts: 67
Re: a few things about this

Thanks for the recommendation. I will consider it.

 Sinawang's gear list:Sinawang's gear list
Canon EOS RP Canon EF 16-35mm F4L IS USM Canon 85mm F1.4L IS USM Canon RF 50mm F1.8 STM Canon RF 70-200 F4 L +1 more
MannyV
MannyV Contributing Member • Posts: 907
Re: a few things about this
2

Sinawang wrote:

Thanks for the recommendation. I will consider it.

Singapore there are plenty of options. The shipping cost will be expensive as these cabinets are heavy. Most photography equipment shops in humid countries of Asia will have stocks of dry cabinets. I have lived in SG, MY, Indonesia, Thailand, and Philippines. The photo stores in these countries carry a lot of decent dry cabinets.

The advice to call Canon is good advice. I got excellent service from Canon Singapore when I went for 5D II repair long time ago. I had got it used and the seller didn't tell me it had water issues and of course during the usual test at buying I didn't find anything amiss. It was only a couple of week or so later the water related corrosion happened. Canon had to replace main board, shutter assemble, mirror box. I got a practically a new camera. Canon was reasonable and charged me less than a 1000 SGD for the repair. That camera worked well and served me good. All I am saying is while camera companies say they won't honor water related issues like fungus or corrosion, they usually put it to prevent abuse. Ever seen YouTubers washing their camera under shower and boasting about it? I see that as abuse to be honest.

Anyways wish you lots of luck. Hopefully it will resolve.

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Manny
Still draft and working towards it - https://www.digitalphoto.work

PicPocket Veteran Member • Posts: 4,853
Re: Fungus (?) inside RF 70-200 F4 L
1

Sinawang wrote:

What I'm asking is not about if the seals are air tight or not, but the integrity of the seal from preventing dust particles which are relatively bigger than air particles, where fungus spores might sticks on that dust particles, hope that make sense for Canon to understand this issue.

How do you know the integrity of seals is compromised? What specifications are the seals? You might have seen the seal on the lens mount - that exists to save the lens from water seeping in when lens is mounted on a weather sealed body. That means, when it's not mounted to such a body, the back is not protected.

More importantly, fungus grows well in moist less ventilated spaces. So the same sealing that keeps water out, also helps fungus grow once it is in. A weather sealed lens isn't very well ventilated

Weather sealed is not waterproof. It's also not hermetically sealed. If it was, manufacturers will proudly claim so. So rather than focus on seals, focus on getting your lens in order if it's really fungus. Call Canon, and ask nicely. They might help

Since you are in Asia, you might be able to find eureka dry cabinets. It's a Taiwanese company I have used for about 15 years. Simple and effective

But even before all that, take care of your lens. If fungus stays in, it will eventually grow

https://www.dyxum.com/dforum/weather-sealed-fungus-free_topic90256.html

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 PicPocket's gear list:PicPocket's gear list
Canon EOS M50 Canon EOS R5 Canon EF 85mm F1.8 USM Tokina AT-X Pro 11-16mm f/2.8 DX Sigma 150mm F2.8 EX DG Macro HSM +15 more
OP Sinawang Forum Member • Posts: 67
Re: Fungus (?) inside RF 70-200 F4 L

PicPocket wrote:

Sinawang wrote:

What I'm asking is not about if the seals are air tight or not, but the integrity of the seal from preventing dust particles which are relatively bigger than air particles, where fungus spores might sticks on that dust particles, hope that make sense for Canon to understand this issue.

How do you know the integrity of seals is compromised?

Dust particles. I see some dust particles, 2 on the front element which one of them has kind of radial halo like something grows from that single dust, and single bigger dust particle on the rear element. I don't know how they got inside the lens barrel.

What specifications are the seals? You might have seen the seal on the lens mount - that exists to save the lens from water seeping in when lens is mounted on a weather sealed body. That means, when it's not mounted to such a body, the back is not protected.

More importantly, fungus grows well in moist less ventilated spaces. So the same sealing that keeps water out, also helps fungus grow once it is in. A weather sealed lens isn't very well ventilated

Weather sealed is not waterproof. It's also not hermetically sealed. If it was, manufacturers will proudly claim so. So rather than focus on seals, focus on getting your lens in order if it's really fungus. Call Canon, and ask nicely. They might help

Since you are in Asia, you might be able to find eureka dry cabinets. It's a Taiwanese company I have used for about 15 years. Simple and effective

But even before all that, take care of your lens. If fungus stays in, it will eventually grow

https://www.dyxum.com/dforum/weather-sealed-fungus-free_topic90256.html

I suspect the fungus is already with the dust and the dust got inside the lens then ended up on the front element and the suspected fungus eventually moving from the dust particle and spreading to the glass.

Here's after 24 hr I buried the lens with all the silica gel sachets I have while waiting my dry cabinet & UV light shipped.

From different angle you can see that kind of halo around the dust. It doesn't spread further as I worried. That's still the same size when I first saw it 2 days ago. The centre dot is the dust and there are another dust there in the back of the front element.

This stresses me out. The only relief is that it's not seen in the frame as it's outside the coverage area of the sensor.

I'll call canon today and see what I can get.

 Sinawang's gear list:Sinawang's gear list
Canon EOS RP Canon EF 16-35mm F4L IS USM Canon 85mm F1.4L IS USM Canon RF 50mm F1.8 STM Canon RF 70-200 F4 L +1 more
PicPocket Veteran Member • Posts: 4,853
Re: Fungus (?) inside RF 70-200 F4 L

Sinawang wrote:

PicPocket wrote:

How do you know the integrity of seals is compromised?

Dust particles. I see some dust particles, 2 on the front element which one of them has kind of radial halo like something grows from that single dust, and single bigger dust particle on the rear element. I don't know how they got inside the lens barrel.

not saying it didn’t happen due to bad seals. But it might as well have gone in when the lens wasn’t mounted on a weather sealed body. Or it got into the body first and then got sucked into the lens. A few dust specs getting into the lens isn’t that surprising

Here's after 24 hr I buried the lens with all the silica gel sachets I have while waiting my dry cabinet & UV light shipped.

silica gel only deals with moisture, not fungus. Sunlight and ventilation is your friend until your equipment arrives. Even the dry box is prevention, it won’t kill fungus directly

This stresses me out. The only relief is that it's not seen in the frame as it's outside the coverage area of the sensor.

no, it’s not visible because it’s much closer to lenses MFD. the lens cannot focus it onto the sensor, so it gets spread out and given it’s small you don’t see any obvious impact.

I'll call canon today and see what I can get.

good luck. Keep us posted. Curious on end result

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 PicPocket's gear list:PicPocket's gear list
Canon EOS M50 Canon EOS R5 Canon EF 85mm F1.8 USM Tokina AT-X Pro 11-16mm f/2.8 DX Sigma 150mm F2.8 EX DG Macro HSM +15 more
OP Sinawang Forum Member • Posts: 67
Re: Fungus (?) inside RF 70-200 F4 L

PicPocket wrote:

not saying it didn’t happen due to bad seals. But it might as well have gone in when the lens wasn’t mounted on a weather sealed body. Or it got into the body first and then got sucked into the lens. A few dust specs getting into the lens isn’t that surprising

Yeah that make sense.

Here's after 24 hr I buried the lens with all the silica gel sachets I have while waiting my dry cabinet & UV light shipped.

silica gel only deals with moisture, not fungus. Sunlight and ventilation is your friend until your equipment arrives. Even the dry box is prevention, it won’t kill fungus directly

I just try as much as I can to suffocate it by taking out as much moisture as I can to prevent it grow further.

This stresses me out. The only relief is that it's not seen in the frame as it's outside the coverage area of the sensor.

no, it’s not visible because it’s much closer to lenses MFD. the lens cannot focus it onto the sensor, so it gets spread out and given it’s small you don’t see any obvious impact.

It also is the possible case

I'll call canon today and see what I can get.

good luck. Keep us posted. Curious on end result

 Sinawang's gear list:Sinawang's gear list
Canon EOS RP Canon EF 16-35mm F4L IS USM Canon 85mm F1.4L IS USM Canon RF 50mm F1.8 STM Canon RF 70-200 F4 L +1 more
Karl_Guttag Senior Member • Posts: 1,152
Re: Fungus (?) inside RF 70-200 F4 L
1

Sinawang wrote:

<snipped>

I suspect the fungus is already with the dust and the dust got inside the lens then ended up on the front element and the suspected fungus eventually moving from the dust particle and spreading to the glass.

Here's after 24 hr I buried the lens with all the silica gel sachets I have while waiting my dry cabinet & UV light shipped.

From different angle you can see that kind of halo around the dust. It doesn't spread further as I worried. That's still the same size when I first saw it 2 days ago. The centre dot is the dust and there are another dust there in the back of the front element.

This stresses me out. The only relief is that it's not seen in the frame as it's outside the coverage area of the sensor.

I'll call canon today and see what I can get.

Please, don't get stress out. It is not that bad (yet).

First, ALL lenses have dust in them, and they will get more dust with time, even the best L lenses in the world. You can't have lenses that move in and out and seal against all dust. Also, note that waterproof is not the same as vapor proof. No lens is mold spore proof as mold spores are very tiny.

The good news is that if the dust and other imperfections are not near the sensor, they will not appear in the image. Note that even if the dust spot is on the sensor filter (just before the sensor), you can't see them until you stop down, generally to f16 or smaller. I don't think it happens today, but back when Canon used to say that a few bubbles in the glass were "normal" even for L lenses and would not degrade the image quality.

To a first approximation, all parts of the lens contribute to all parts of the image. So even if that mold spot were a black dot, you probably would not notice it even if you shot a picture of a white object. All the spot does is dim the whole image by the percentage of the light that is blocked (which is probably much less than 1%).

For a very simple but dramatic and simple example, see this video at the point linked to here: https://youtu.be/acmDxmEAiDM?t=489.

Also, it appears that this is occurring on the outer part of the lens, which primarily contributes to the image only at the wider apertures so that it will be even more out of focus/invisible if it has any effect at all.

It is kind of like you scratched the outside of the lens. It does not make you feel good, but it is not hurting the image significantly.  Take some pictures of a white sheet of paper or some other uniform white object at various apertures and see if you can see it.

That said, since you live in a humid climate, you don't want it to get worse. You could get a nasty surprise someday when you put a lens out that you have not used for a long time. Also, mold can eat at the lens coatings and not be reversible via cleaning. You definitely want to take precautions regarding Humidity and UV light to kill/control the mold.

Even if you were to kill all the mold in the lens today, you would get more tomorrow. All lenses have microscopic mold spores in them. If they get water vapor, then they will grow. You have to keep the humidity down and kill them with UV (sunlight counts) light.

 Karl_Guttag's gear list:Karl_Guttag's gear list
Canon EOS R5 Canon RF 15-35mm F2.8L IS USM Canon RF 24-70mm F2.8L IS USM Canon RF 70-200mm F2.8L IS USM Canon RF 24-240mm F4-6.3 +13 more
OP Sinawang Forum Member • Posts: 67
Re: Fungus (?) inside RF 70-200 F4 L

Karl_Guttag wrote:

Please, don't get stress out. It is not that bad (yet).

First, ALL lenses have dust in them, and they will get more dust with time, even the best L lenses in the world. You can't have lenses that move in and out and seal against all dust. Also, note that waterproof is not the same as vapor proof. No lens is mold spore proof as mold spores are very tiny.

The good news is that if the dust and other imperfections are not near the sensor, they will not appear in the image. Note that even if the dust spot is on the sensor filter (just before the sensor), you can't see them until you stop down, generally to f16 or smaller. I don't think it happens today, but back when Canon used to say that a few bubbles in the glass were "normal" even for L lenses and would not degrade the image quality.

To a first approximation, all parts of the lens contribute to all parts of the image. So even if that mold spot were a black dot, you probably would not notice it even if you shot a picture of a white object. All the spot does is dim the whole image by the percentage of the light that is blocked (which is probably much less than 1%).

For a very simple but dramatic and simple example, see this video at the point linked to here: https://youtu.be/acmDxmEAiDM?t=489.

Is the point you trying to show me in that video is at the 8:35 time mark?

Also, it appears that this is occurring on the outer part of the lens, which primarily contributes to the image only at the wider apertures so that it will be even more out of focus/invisible if it has any effect at all.

It is kind of like you scratched the outside of the lens. It does not make you feel good, but it is not hurting the image significantly. Take some pictures of a white sheet of paper or some other uniform white object at various apertures and see if you can see it.

That said, since you live in a humid climate, you don't want it to get worse. You could get a nasty surprise someday when you put a lens out that you have not used for a long time. Also, mold can eat at the lens coatings and not be reversible via cleaning. You definitely want to take precautions regarding Humidity and UV light to kill/control the mold.

Even if you were to kill all the mold in the lens today, you would get more tomorrow. All lenses have microscopic mold spores in them. If they get water vapor, then they will grow. You have to keep the humidity down and kill them with UV (sunlight counts) light.

Thanks. Lesson learnt!

 Sinawang's gear list:Sinawang's gear list
Canon EOS RP Canon EF 16-35mm F4L IS USM Canon 85mm F1.4L IS USM Canon RF 50mm F1.8 STM Canon RF 70-200 F4 L +1 more
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