Inner fungal bloom issue, 6 month old Canon ef 70-300 L

The 70-300L is weatherproof, but not fully waterproof and certainly not airtight. Also it's only weatherproof when mounted on a body - the rear is completely open. If you're working in a very humid environment you need to take appropriate precautions, even with a weatherproof lens.

Steve Balcombe wrote:

The 70-300L is weatherproof, but not fully waterproof and certainly not airtight. Also it's only weatherproof when mounted on a body - the rear is completely open. If you're working in a very humid environment you need to take appropriate precautions, even with a weatherproof lens.

Thanks, but such as what? I have a filter and lens cap attached all the time, the lens cap only coming off when taking a pic, and the lens is either attached to the camera body or has the appropriate cap on the mount and kept in a bag.That should be adequate, especially for a pro lens. My efs 10-22 and crappy early 18-55 (non IS) don't have any such blooms, and the 18-55 doesn't even have a filter attached.

I'm sorry, but the L series lens should not have this affliction.

sanderspics wrote:

Steve Balcombe wrote:

The 70-300L is weatherproof, but not fully waterproof and certainly not airtight. Also it's only weatherproof when mounted on a body - the rear is completely open. If you're working in a very humid environment you need to take appropriate precautions, even with a weatherproof lens.

Thanks, but such as what? I have a filter and lens cap attached all the time, the lens cap only coming off when taking a pic, and the lens is either attached to the camera body or has the appropriate cap on the mount and kept in a bag.That should be adequate, especially for a pro lens. My efs 10-22 and crappy early 18-55 (non IS) don't have any such blooms, and the 18-55 doesn't even have a filter attached.

I'm sorry, but the L series lens should not have this affliction.

And I'm genuinely sorry to be the bearer of bad tidings, but did you not actually understand my reply? Both the humidity and the fungal spores are carried in the air. To keep that level of humidity out of a piece of equipment for months on end it would need to be airtight.

I've never been fortunate enough to travel in that area, but people who live and work there go to great lengths to avoid this problem - even buying special cabinets to keep their gear in.

biza43 wrote:

As Steve said, this happens in humid and hot climates. The lens is not airtight, and the zooming in-out actions will suck air inside the lens.

My sample of the lens has now gathered some dust inside the barrel from precisely this reason. With time, zoom lenses will gather "stuff" inside, because they are not airtight. In such climates as SE Asia, you have to invest in special cabinets to store your gear.

what do such cabinets? i think when you store your lens in such things you are not realy zooming it in and out all the time, so when you take it out the cabinet to use you still have the same problem, or am i wrong?

Not sure I understand the question.

No matter where you bought the lens, find out what Canon service center does the warranty work for that region and ship it to them with a copy of your receipt.

I've found that if moving from an air conditioned environment to the outside in very hot humid climates such as in Thailand, relatively cold cameras and lenses can almost instantly fog up with condensation and some of this can form on internal lens elements.  Usually it dries out OK but presumably any residual moisture is a perfect breeding ground for fungal spores.

Try putting equipment into sealed plastic bags and allowing it to warm up to the ambient temperature before opening the bag, which largely resolves the condensation problem.  This can take 15 minutes or more which is a bit of a pain but maybe that's preferable to suffering from condensation and fungal issues.

... and consider using desiccants where ever the gear is stored.  I have about 4 'Eva-Dry' "dehumidifier" units which are regenerated by plugging them into a wall outlet for several hours (hence the multiple units).  New England USA isn't always humid but it's almost always climate challenged and moving from cold and dry to warm and humid is nearly a year-round issue.

Certainly send it to Canon with your complains but your gear will last longer and operate more reliably if you take better care.

-Mark

meland wrote:

I've found that if moving from an air conditioned environment to the outside in very hot humid climates such as in Thailand, relatively cold cameras and lenses can almost instantly fog up with condensation and some of this can form on internal lens elements. Usually it dries out OK but presumably any residual moisture is a perfect breeding ground for fungal spores.

Try putting equipment into sealed plastic bags and allowing it to warm up to the ambient temperature before opening the bag, which largely resolves the condensation problem. This can take 15 minutes or more which is a bit of a pain but maybe that's preferable to suffering from condensation and fungal issues.

Also, take it out when you return to the air conditioned room. Leaving it in the bag overnight so the previous day's humidity is trapped, could be the worst thing to do.

Even in the UK I make a point of emptying my bag if I've been out in the rain.

photonius wrote:

Using a filter may have made things worse for the front lens, since you may have trapped most air in there. Put the filter on in dry conditions.

It certainly won't have helped. But also the 70-300L is one of the first lenses to have Canon's fluorine coating, which is incredibly effective in repelling marks, dust and water. Adding a filter simply deprives the lens of all the benefits of this coating.

Well I'll run some test shots off and check for any other problems. Close up shots at 300 are excellent, but more distant shots are not as sharp as I'd expect and a bit flarey/washed out especially with a lot of light to deal with. . . . perhaps I'm expecting too much. I like the Lensrental article on scratched front elements. . . . thanks

I fitted the filter in the mall where it was purchased. I also read that the lens isn't weather proof without a filter on the front and I wouldn't fancy carrying this lens around without the lens hood with no filter attached, as it protrudes quite a way and the front element would be easy to damage. Its not as if I can shell out for a lens like this very often.

I guess I'm going to be stuck with the mould blooms, fork out a lot in repairs, or ship half way around the world for an uncertain outcome. I just hope the blooms prove not to be a noticeable issue with this lens and that they wont get worse.

Thanks for the relies guys

I've cleaned out a bunch of lenses, newly formed fungus that's right behind the front element usually isn't a difficult repair.  You might not want to do it yourself (taking apart an expensive lens isn't high in my list either), but I'd be surprised if you couldn't find a repair shop either in Thailand or back in the UK that would do it inexpensively, if the warranty isn't going to be valid anyway there's.  A lot of UV light will kill any living spores in the mean time, if you have access to a UV source.

From reports I've read on here there's a good chance that if sent to Canon for warranty service, it would be declined since it is not a defect in the lens it self.  Where the moisture got inside the lens is anyone's guess.  Could have been when you had it or when Canon had it but they probably have a very controlled assembly area for lenses.

photonius wrote:

sanderspics wrote:

Well I'll run some test shots off and check for any other problems. Close up shots at 300 are excellent, but more distant shots are not as sharp as I'd expect and a bit flarey/washed out especially with a lot of light to deal with. . . . perhaps I'm expecting too much.

If close distance is good, did you consider athmospheric conditions might influence longer distance shots? the air in places like bangkok sure is nothing to write home about.

I tried to shoot some old temple spires of Ayutthaya from a hotel on the outskirts with my 55-250IS - through some not so great morning smog. Looks really rather murky, worse than I remember.

I like the Lensrental article on scratched front elements. . . . thanks

just to give an idea how such things impact the image. Still, one would expect some contrast loss in counterlight situations with your mold. try to get it cleaned and at least try to keep it very dry, otherwise it will spread - that's the biggest issue.

Yes of course the atmosphere does indeed affect the distance shots, right now looking out over the mountain range nearby there is a lot of haze there, but that's not what I am referring to, its mainly in the counterlight situations where I am noticing some flaring.  Thanks for your rely mate