Is this moisture or dust?

I just received a lens yesterday, and I'm concerned that there is something on one of the elements that is not dust. I've attached two pictures that are not the best, but still show the unique pattern. I don't think dust would look like this, but wanted to see what others thought.

EDIT: The first one shows the best what it looks like. It is in the middle of one of the center elements.

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Strange how it's so uniform.

FarmerTed1971 wrote in post #16439748
Strange how it's so uniform.

That's why I'm concerned that it's not just dust.

Was the lens shipped ground or air?

koala yummies wrote in post #16439765
Was the lens shipped ground or air?

Ground. It's been sitting in a dry, sealed bag since yesterday when I received it and it looks the same as when I first pulled it out of the box. It came from Florida to Texas, so it didn't really pass through any extreme temperature changes.

whmeltonjr wrote in post #16439769
Ground. It's been sitting in a dry, sealed bag since yesterday when I received it and it looks the same as when I first pulled it out of the box. It came from Florida to Texas, so it didn't really pass through any extreme temperature changes.

Ok that eliminates the possibility I was thinking of (bubbles from lens element glue separation).

koala yummies wrote in post #16439781
Ok that eliminates the possibility I was thinking of (bubbles from lens element glue separation).

I didn't think it was that either. I've seen dust in lenses before, but nothing lined up in a pattern like that which is why I believe it is moisture.

Dust wouldn't be that uniform. The remains of H2O condensation would look evenly spaced like that. Your lens might have gone for a swim. Another lesson for me not to be tempted to buy used gear. Too easy for ethically compromised people to dump damaged goods on unsuspecting buyers.

How old is it? Is it possible the coating is failing?

joedlh wrote in post #16439845
Dust wouldn't be that uniform. The remains of H2O condensation would look evenly spaced like that. Your lens might have gone for a swim. Another lesson for me not to be tempted to buy used gear. Too easy for ethically compromised people to dump damaged goods on unsuspecting buyers.

I didn't think there was any possibility for dust to lay out like that either. I showed it to another photographer and he agreed with my suspicions without me sharing what I thought it was.

Fungus?

it's not fungus, or dust...is the lens a sigma 70-200mm f2.8 by chance?

see this thread...it looks like exactly what you have...i think the final consensus was element separation
https://photography-on-the.net …hlight=Element+​separation

DreDaze wrote in post #16440852
it's not fungus, or dust...is the lens a sigma 70-200mm f2.8 by chance?

see this thread...it looks like exactly what you have...i think the final consensus was element separation
https://photography-on-the.net …hlight=Element+​separation

No, it's not a Sigma. It does look the same though. Thanks for the link.

FL...high humidity and high temps...I'd be wary of buying used from there (sorry ppl who live there, I can't stand the place) as those are two things that electronics and optics really don't like.

What lens is it?

Looks exactly like that separation issue in the other thread.