What are the spots on my old 35mm Summilux' front element?

[Tijmendal]

Hi,

I recently got this Summilux in the mail and I noticed there's these weird spots on it. I tried taking pictures of it, but it's not very clear.
They're spots on the front element. They looked like specs of dried yoghurt to me (but they're not, obviously)

I tried very carefully see if I could rub them off, but to no avail. When using a toothpick to lightly run over the surface of the lens, I feel little bumps as I touch them. With my fingernail I didn't feel anything, but the toothpick trick worked.

Could it be fungus? The surface is clear otherwise

EDIT:
Made a better picture; I think it's pretty clear what's going on here:

 

[Erik van Straten]

I think it is fungus. The glass is eaten away by microbes. That is why you can feel it with the toothpick.

It is a pity for this good looking lens, but I would return it to the seller. It can grew worse.

On the last picture things look really bad.

Erik.

 

[sevo]

Might be the results of past fungus, or droplets of some substance that stick to the lens (or damaged the coating). Ever photographed near a building site, or inside an industrial plant? Or in a kitchen, or children playing with liquids?

 

[raid]

I would return lens. Even if the you got the price down by $1000, it may cost you $500 to get the lens cleaned/repaired and the lens is still imperfect.

 

[benmacphoto]

I would return it.
Aside from those bumps, there are a lot of cleaning marks, which could affect the image quality of the lens.

 

[Tijmendal]

I would return lens. Even if the you got the price down by $1000, it may cost you $500 to get the lens cleaned/repaired and the lens is still imperfect.

I paid 700€ for it, so it's a good price. But if it can't be cleaned/restored, then it's not really worth keeping I reckon.

I think it is fungus. The glass is eaten away by microbes. That is why you can feel it with the toothpick.

It is a pity for this good looking lens, but I would return it to the seller. It can grew worse.

On the last picture things look really bad.

Erik.

Erik, thanks for sharing your knowledge. Can't it be cleaned up?

 

[Erik van Straten]

I paid 700€ for it, so it's a good price. But if it can't be cleaned/restored, then it's not really worth keeping I reckon.



Erik, thanks for sharing your knowledge. Can't it be cleaned up?

The only thing is to replace the front lens or to have it repolished and recoated. You can ask CRR Luton (Peter Grisaffi) or Malcolm Taylor (UK). Maybe they do things like this. Malcolm Taylor has repolished the front element of Mr. Fibble's (Rick van Nooij) Hektor 50mm.

If the fungus is still active, it can attack your other lenses, so watch out.

Erik.

 

[Huss]

Before u get return the lens try gently rubbing it off with some 91% isopropyl alcohol (rubbing alcohol from a pharmacy) on a q tip (cotton swab). I have removed spots like this using this method.

 

[fad gadget]

I'd say try Huss's suggestion and if that fails return it.

I just picked up a mint, recently CLA'd one for almost a hundred quid less.

Hope it works out.

cheers/ken.

 

[Timmyjoe]

I agree with Ken, try Huss's suggestion, then return it.

Front of the lens does look pretty dirty, not sure if what we can see in the second picture is cleaning marks or residue from past cleaning that wasn't removed. I'd try the alcohol and some lens cleaning fluid, with lens tissues (not toothpicks and fingernails), and see if it cleans up. I've gotten lenses from the auction site that looked terrible, until I properly cleaned them, then they were fine.

 

[David Hughes]

I'd look at the spots with a x20 lens first.

Regards, David

 

[jaapv]

If somebody sells a lens in this state... Return it.

 

[pgk]

The only thing is to replace the front lens or to have it repolished and recoated. You can ask CRR Luton (Peter Grisaffi) or Malcolm Taylor (UK). Maybe they do things like this. Malcolm Taylor has repolished the front element of Mr. Fibble's (Rick van Nooij) Hektor 50mm.

Erik.

I'm pretty sure that I've discussed this with Malcolm and in this case re-polishing isn't possible with the 35 pre-asphric Summilux as the front element is quite thin and actually very difficult to re-polish. That said, I'm not convinced that the spots are fungus, and my guess would be that the circles might be due to water droplets which have caused oxidation of the surface of the glass (this happens on underwater mineral glass ports if they aren't cleaned and dried after use - the surface remains damp and oxidises). That said I doubt that they will significantly affect performance other than increase flare (which can be bad at times with this lens anyway. Whatever the cause the lens is significantly devalued as a result.