Fungus among us?

[pato]

Howdy Ho!

I bought a used 25mm Voigtlander LTM lens a while back. When changing lenses recently I noticed some strange dots on the back of the optics:

I can't tell whether it's in the glass, or on the surface of the housing.

And, I'm not sure if it's a fungus or not, but it doesn't look like any of the pictures I was able to find online.

Anyone care to weigh in on this?

Thanks,
Pato

 

[cassel]

I have an old Nikkor screwmount lens with exactly the same small dots/marks on the rear element--- diagnosed as fungus🙁

Your lens is much newer, perhaps/maybe/hopefully it is something else?

Second look: It does seem like maybe the dots are on the metal not the glass-- see the way they follow the contours of the curves?

 

[alistair.o]

Have you tried to wipe it/clean it (gently)? Don't be afraid of doing this.

If it does not come off then I'd say take a good look for lubrication in the lens i.e. blades etc. Have you kept the lens in a hot place (for arguments sake?)

 

[stompyq]

That looks like schneideritis. Not fungus. I had quite a few large format lenses with this defect and never saw any ill affects compared to those that didn't have it. There are discussions on if it affects image quality or not online. Search for them. Overall I would not worry one bit. You might have a problem if your going to resell but for general use I would not think about it

 

[tunalegs]

The outside edges of lens elements are painted black to help increase contrast. When that paint starts to bubble you get exactly what you have. It will have no effect on image quality and is not something to worry about too much.

 

[pato]

thanks to those of you who answered. I was never notified that someone had replied, and only now realized that I had not subscribed to my own question (would think that s a default setting).

Anyway, I'm pretty sure that the spots are in the lens, not the paint. Unfortunately, this doesn't come out in the lo-res versions of the pictures I was able to upload here.

The lens has been stored in a camera bag with those silica gel packs in it to reduce moisture.

Haven't noticed any reduction in quality: https://www.flickr.com/photos/patito/15196049377/in/album-72157600224456784/