Technician recommendation for enlarging lens cleaning

[0x001688936CA08]

I'm looking to have an enlarging lens cleaned of internal dust, or at least have a skilled tech advise whether cleaning is possible / worthwhile.

I'm in Seattle, willing to send the lens for inspection.

 

[Ivo Stunga]

Is that dust creating problems?
There can be quite large particles inside/on elements without any I'll effect.

 

[0x001688936CA08]

It is not (as far as I can tell).

However I'm considering selling the lens, and a clean copy is likely worth considerably more than a dusty one.

 

[mshchem]

Is it dust or fungus?

 

[0x001688936CA08]

Dust.

Pretty sure:

 

[mshchem]

Hmmn? Almost looks like Schneideritis, paint on lens element edges coming off. Looks like a big lens. Enlarging lenses can be difficult to sell.

 

[mshchem]

Shouldn't be a big deal for a quick cleaning.

 

[0x001688936CA08]

Yeah, it does look sort of like Schneideritis (it is a Schneider APO-Componon HM 4/150), but it's particles of something spread across on internal lens surface.

If anyone has a recommendation for a good tech please let me know.

 

[F4U]

I wouldn't give it another thought.

 

[koraks]

Yeah, it does look sort of like Schneideritis (it is a Schneider APO-Componon HM 4/150), but it's particles of something spread across on internal lens surface.

Are you sure? It really looks like plain old Schneideritis to me. This can appear as particles spread out across a lens element, but in reality it's a bit of an optical illusion. If it is Schneideritis, there's nothing that can or should be done about it; it's harmless.

W.r.t. having this professionally cleaned (if that's needed, which I doubt), I wonder whether the costs of having that done weigh up to the supposedly higher price you'll fetch for it.

Frankly, I'd just verify if this really is Schneideritis and then put it up for sale as-is.

 

[Ian C]

I agree with the others. It appears to be bubbling in the light-absorbing coating applied to the outside diameter of each element. It’s simply the separation of the material from the OD in small, usually circular, spots as it ages.

Contrary to the “Schneideritus” term, this happens to other makes of lenses as well. I have a Fujinon large-format lens with such a bubbling pattern. Although cosmetically annoying, it does no harm to the performance of the lens.

Although theoretically possible to disassemble the lens, remove the old material, recoat and reassemble, it's impractical and would be prohibitively expensive. So far as I’m aware, no business offers such service.

 

[xkaes]

Yup, it's meaningless -- except to potential buyers. I bought a Fujinon lens with a similar non-problem. Works great, and I got it for a great price. Good luck.