Summicron DR separation vs fungus vs other

[bvsedsosa]

Recently purchased this lens on eBay. I noticed this flaw at the edge of the rear element, can anyone tell me what it is?

 

[Larry H-L]

It is difficult to say for certain looking at small photos, but perhaps a bit of slight edge separation, or possibility Schneideritis which is a bubbling of glue/paint where glass meets the inside of the barrel. It doesn't have the spider web appearance of fungus to me.

In any case, it appears to be minor and way at the edge of the glass, so I think it is unlikely to show in your images. It is difficult to find a perfect 60+ year old lens.

 

[stompyq]

That looks like separation to me. I would return it if possible. Unless you got a very good deal. It can worsen over time or remain with no change

 

[bvsedsosa]

Thanks guys, I think I’ll return it . I don’t want to risk it getting worse as Youxin has confirmed that it is unfixable