So where do you draw the line??

So I was cleaning my lenses last night. When I looked thru my 70-200II I can see a few small specs/dust/spots on the front element inside.

Now I'm no perfectionist and I often read on here that no lens is perfect, that is a few dust inside is quite normal and nothing to worry about. But how can I tell if it isn't an early signs of fungus??

The fear of it ruining my lens is unbearable, and the chances of it spreading onto my other lenses is daunting me.

So where do you draw the line? Just ignore it and deal with it if it gets worse? Leave it out in the sun periodically?? Send it back to have it cleaned?

Living in Sydney, I doubt it's likely to be fungus.
I wouldn't worry about it.

Fungus will be obvious when you see it. it will look fuzzy at the start then gradually grow and have little arms. But I seriously doubt it's fungus.

philwillmedia wrote in post #15497914
Living in Sydney, I doubt it's likely to be fungus.
I wouldn't worry about it.

I wish that's the case...

Just checked my Sigmalux and I can definitely see a few iffy spots on the front element.

It's definitely more than just 'dust'.

pics ?

What causes a lens fungus? And does it spread to your other lens?

michgirl wrote in post #15498022
What causes a lens fungus?

I really dunno!!

I'd say not yet...but I am scared

It hasn't grown any arms or legs yet. It's just a spot which looks like an early stage.

am going to take a pic now..

Spores+moisture+darkne​ss. Yes it does spread.

Some dust is normal. As mentioned fungus looks like webs.

michgirl wrote in post #15498022
What causes a lens fungus?

Essentially, prolonged moisture and humidity.

michgirl wrote in post #15498022
And does it spread to your other lens?

It can

Just took a photo of the front element with my 100L. Yup definitely fungus

https://www.dropbox.co​m/sh/mvztk55fvg0cyhp/q​PVNW5SMAz

kin2son wrote in post #15497625
So I was cleaning my lenses last night. When I looked thru my 70-200II I can see a few small specs/dust/spots on the front element inside.

Now I'm no perfectionist and I often read on here that no lens is perfect, that is a few dust inside is quite normal and nothing to worry about. But how can I tell if it isn't an early signs of fungus??

The fear of it ruining my lens is unbearable, and the chances of it spreading onto my other lenses is daunting me.

So where do you draw the line? Just ignore it and deal with it if it gets worse? Leave it out in the sun periodically?? Send it back to have it cleaned?

I bought my 70200MK2 the same week it was released for $2500 and it came preloaded with one spec of visible dust behind the front element, but the lens is super sharp across the range and the dust did not affect when stopping down so I decided to just ignored it, if i returned for exchange i may end up with a less sharp copy, if i send it to canon then i risk having the lens being mishandled by the delivery guy and at shipping dock being kick around. If i were you i'd ignore it if the lens perform as expected, you are buying a tool so use it to its full potential.

Doesn't look like fungus to me. Is it white?

GregoryF wrote in post #15498149
Doesn't look like fungus to me. Is it white?

It is kind of....I point the lens towards the sun and therefore it looks black (underexposed).

michgirl wrote in post #15498022
What causes a lens fungus? And does it spread to your other lens?

The fungus spore and high humidity or moisture. Dust is a great vector to introduce the spore. It would not surprise me if every single dust speck on the planet has the lens fungus spore attached. It's everywhere. When conditions are right, the spore sprouts and the fungus starts growing.

Ouessant wrote in post #15498030
Spores+moisture+darkne​ss. Yes it does spread.

I'm not sure that spread is really the right term. The spores are probably already in all our lenses. But if you have one lens which is showing a lens fungus, odds are that the other lenses stored the same way will get it as well leading one to believe that it's jumping from lens to lens.