from the article: "The takeaway message, though, is in the picture you can't see here. We took dozens of images with the lens before taking the fly out. We shot stopped down, we shot at all parts of the zoom range. We focused close, we focused far. And in no image could we find the slightest hint that there was a fly in the lens. And you guys worry about a dust particle or two!"
Take a few images with the lens and let us know if you can see anything. I'm curious to know. And if you can feel reasonable certain your UV hood can kill it, then maybe a make a reasonable offer (something you can live with knowing that sometime down the road, the fungus could grow and make it unusable.)
p.2 #2 · Correct pricing for lens with slight fungus?
What Jim said about etching the optics.
The UV will kill it. Problem is, the inside of lenses are designed not to reflect light, so any fungus on the barrel, in little nooks and crannies, etc....may very well not be effected. If you could remove the rear, and front, element groups and put a black light fluorescent tube into the barrel, this would likely help a lot. Just UV shining into the lens will only likely effect fungus on the optics.
As for removing the left overs after killing it off, I've used a 50/50 mix of ammonia and h2o2. Careful with H2O2...the high strength (30%+) stuff is nasty, caustic and cause tissue damage. I've used drug store 3% stuff. This combination should also kill it with higher strength h2o2. However, it can create an exothermic reaction and spontaneously combust. Caution must be used.
As for etched optics, not much you can do. The only real way to tell, that I know of, is to roll the dice, clean the mold and inspect for etched glass afterwards.
p.2 #3 · Correct pricing for lens with slight fungus?
I would suspect severly etched optics to effect IQ, unlike the fly. The etching is actually effecting the original optical formula, vs something just being in the way. I could be wrong though and it may not be noticeable at all with minor etching damage. Depends on how far its etched into the optics.
p.2 #5 · Correct pricing for lens with slight fungus?
PetKal wrote:
Luis Fraga ("Fraga") had a major problem with EF lens element fungus,
I see that my previous posts with pictures have left a long lasting impression with you!
To the OP: I live in a place with very high humidity levels.
At one time, I sold my camera and pre-ordered the 50D.
I had to wait 3 months for it (long story short: it was stolen at the postal office and the seller had to send me another one, after 2 or 3 weeks of failed attempts of locating the missing package).
Meanwhile, my lenses were left stored in the backpack unattended during this period (I know... I know...).
Result: major fungus infestation in three lenses.
I have posted the images here more than once, until some users (I won't accuse Petkal... ) asked me not to do it anymore, since someone might have a heart attack.
Well, I had them cleaned with an independent technician.
Sold one of them after awhile (70-200 F4IS, wanted to upgrade to 2.8IS), still have the other two (85L and 135L).
They work perfectly and never had any more fungus issues.
This was several years ago (when the 50d was released).
I can't post the pictures right now, since I'm at work.
Hope this helps.
Jun 11, 2015 at 12:02 PM
AmbientMike Offline • • • • • • [X]
p.2 #6 · Correct pricing for lens with slight fungus?
I haven't read every single post, but to the op
OK, first off, I've bought and used several lenses with fungus. Fungus has little or no effect on sharpness imo. It causes flare. If the flare isn't a problem, you might just leave the fungus there.
From what I understand, the fungus releases hydrofluoric acid. So there may be damage to the lens surfaces even if cleaned. But I'm not sure that's a problem
From what I understand, the fungus is usually or always around, and is a problem when conditions are favorable for it to grow. I don't think the fungus has gotten larger on my lenses that have it
p.2 #8 · Correct pricing for lens with slight fungus?
fraga wrote:
I see that my previous posts with pictures have left a long lasting impression with you!
To the OP: I live in a place with very high humidity levels.
At one time, I sold my camera and pre-ordered the 50D.
I had to wait 3 months for it (long story short: it was stolen at the postal office and the seller had to send me another one, after 2 or 3 weeks of failed attempts of locating the missing package).
Meanwhile, my lenses were left stored in the backpack unattended during this period (I know... I know...).
Result: major fungus infestation in three lenses.
I have posted the images here more than once, until some users (I won't accuse Petkal... ) asked me not to do it anymore, since someone might have a heart attack.
Well, I had them cleaned with an independent technician.
Sold one of them after awhile (70-200 F4IS, wanted to upgrade to 2.8IS), still have the other two (85L and 135L).
They work perfectly and never had any more fungus issues.
This was several years ago (when the 50d was released).
I can't post the pictures right now, since I'm at work.
Thank you Luis, you are a good sport & a friend.
The fact of the matter is that every time you posted those pictures, they had precipitated a major OCD attack, whereby I'd start inspecting, cleaning and airing all of my lenses, and then exposing them to direct sunlight. When one owns 30 or so L lenses, that becomes quite an undertaking.
) asked me not to do it anymore, since someone might have a heart attack. 
