What is this separation?

[kissssss]

Hi, I just gave a Heliar but it had some stains that I don't know what they were. Please tell me know about them. They seem were inside the front group, you can see two stains but there is one and its reflecting image from inner lens.

[IanG]

Looks like balsam separation, it's possible to get the elements re-cemented and some here have done their own.

There's a few companies who can do it but none are cheap.

Ian

[kissssss]

I saw balsam separation on the edges of front and rear group but it's more different. These stains were near the center.

[eddie]

i agree with Ian. separation.

[Steven Tribe]

How old is this Heliar? It is separation. First edge separation with discolouring through time of the balsam exposed to air - then "air holes" and rings elsewhere. Heliars were made over a long period so you could be dealing with unknown wartime ersatz materials or even the first synthetic glues.

[IanG]

It's actually very typical balsam separation, and won't be a modern synthetic.

Ian

[Jim Galli]

Impurity in the cement when originally made?? Make pictures with it. Try not to obsess.

[kissssss]

First, I thought this is the recement liquid, maybe they had recemented this lens, but on the edge I saw the balsam separation, so this was something original... I am not experience about LF lens.

[Steven Tribe]

If this is a purchase, return it. This is too valuable an objective ( and too useful ) to take a risk - it will only eventually get worse.

I think there is a slight possibility that this might be something other (and nastier) than separation. Optical glass is never quite homogeneous and this has the appearance of a very shallow internal fracture through a weakness. But central delamination does have many forms.

[kissssss]

Yes, I should return it... I just wondered what exactly it is.

Thank you very much,