Dead Insect INSIDE Lens

[visigoth]

This is a low-tech question. I just bought a used AIS 105/2.5 -- and there is a dead insect between the elements, towards the edge of the glass. Doesn't seem to affect anything: the lens is super sharp, and I'm seeing no flare (and the bug's too far from the focal plane to appear in the image). BUT:

Is this likely to lead to fungus? I'm in Mexico, so it's not trivial getting a lens CLA'd -- but I will if it's crucial.

 

[IsamuM]

Hi Douglas,

I don't think a dead bug can lead to fungus unless you are in a high humidity environment. However, one wonders how that bug got inside.

Many years ago I heard a story about a moth inside an Olympus lens, but somehow I find the story a bit far fetched.

 

[visigoth]

Kind of hard to figure out. It looks like a large mite, or the like. Perhaps it crawled in when it was really tiny, and grew? (That's not all that probable, itself.)

It is, I assure you, there.

 

[IsamuM]

Hi Douglas,

Don't get me wrong. I don't doubt your story. I'm just not sure how a bug could get into a lens. While lens factories might not be as clean as a semiconductor fab, they are pretty clean.

I guess one possibility is that the lens was in for a repair at one time or another, and taken apart. I don't think all repair facilities are as clean as the factories, so something might get in at such a time.

Anyway, if the bug isn't causing problems with your pics, I'd leave it as it is unless it really bothers you. I have a zoom lens or two that has quite a few specks of dust in it, but that doesn't worry me too much.