For Fun...What Do You Think Is Wrong With This Lens?

[ic-racer]

Top is the picture from the For Sale ad and bottom is my picture before the repair.

 

[ic-racer]

Extra points to guess at the location of the problem:

 

[BHuij]

Someone sneezed a mouthful of cheeto dust on the very front element, and a rocket blower took care of business in 10 seconds flat

 

[ic-racer]

Someone sneezed a mouthful of cheeto dust on the very front element, and a rocket blower took care of business in 10 seconds flat

Warm, but not on the front element.

 

[Harry Callahan]

I'd say it`s between the third and forth element - counting from the front element.

 

[loccdor]

Cement degradation between 5th and 6th?

 

[Harry Callahan]

It rather looks like dust - it could be metal dust, it looks like brass...

 

[loccdor]

I thought about that too. Someone drill into it?

 

[ic-racer]

I have this Zeiss lens that I got in 1984 with what looks like little bubbles between cemented elements. That was my first thought...but it turned out to be wrong for the Nikkor lens in the OP.

 

[ic-racer]

It rather looks like dust - it could be metal dust, it looks like brass...

Ok, yes dust. But from what??? (I did find the source).

 

[Harry Callahan]

As my bet is between the third and fourth element it cannot be from the aperture blades - therefore i bet on the thread of the focusing ring.

 

[ic-racer]

Another hint...

 

[ic-racer]

The answer rhymes with "Venus."

 

[Harry Callahan]

Oh no... bits from the fifths element?

 

[ic-racer]

So far:

It is yellow dust, but not from Cheetos.
It did blow off with a puff of air.
Not glass or metal chips.

 

[loccdor]

The answer rhymes with "Venus."

Is it the latin name for some kind of small insect or mite?

 

[Harry Callahan]

Coating?

 

[Don_ih]

The answer rhymes with "Venus."

Penis? So the lens is f&^ked?

 

[ic-racer]

Very obscure and likely of no use hint: Woolly Mullein

 

[ic-racer]

Another very obscure hint: "Well known Peter Gabriel/Steve Hackett/Genesis song about IVDU"

 

[ic-racer]

Wolly Mullein is Verbascum thapsus. The root of Verbascum is similar to Verbasci.

 

[ic-racer]

That gives us
Rhymes with Venus
Something about Verbasci
Somehing about carpet crawlers.

 

[MattKing]

Some sort of pollen?

 

[loccdor]

Anthrenus?

 

[ic-racer]

Answer: Desiccated eggs and decaying exoskeletons of Anthrenus verbasci larvae -- woolly bears; carpet beetles