tiny bubbles around the edge of a lens

"RolandRB" wrote in message
m...

I've got a lens and it has lots of tiny bubbles under the glass around
the circumference of the lens but not in the middle. Is this the
beginnings of balsam separation?

It was on one of my lenses, but I could also see some yellow discoloration.

RolandRB wrote:

I've got a lens and it has lots of tiny bubbles under the glass around
the circumference of the lens but not in the middle. Is this the
beginnings of balsam separation?

Depends on the age of the lens. In fifties (and sixties, IIRC) there
were some rare-earth doped glass mixes that had bubbles in the glass
mass. They were seen as a proof of high performance.

-- Lassi

In the beginning of 20th century some of the best glasstypes were only
available with bubbles and for that reason bubbles in a lens were considered
as a sign of excellent quality lens.

Jani

"RolandRB" kirjoitti viestissä
m...
I've got a lens and it has lots of tiny bubbles under the glass around
the circumference of the lens but not in the middle. Is this the
beginnings of balsam separation?

RolandRB wrote:

I've got a lens and it has lots of tiny bubbles under the glass around
the circumference of the lens but not in the middle.

What lens is it?
--

Stacey

RolandRB wrote:

Stacey wrote in message ...
RolandRB wrote:

I've got a lens and it has lots of tiny bubbles under the glass around
the circumference of the lens but not in the middle.

What lens is it?

35mm Bessamatic

Is that the focal length? (This is an MF group, remember...)

It could still be one of those rare-earth (e.g. lanthanide) lenses.
Voigtländer was fond of them. What era?

-- Lassi

RolandRB wrote:

Stacey wrote in message
...
RolandRB wrote:

I've got a lens and it has lots of tiny bubbles under the glass around
the circumference of the lens but not in the middle.

What lens is it?

35mm Bessamatic


It's probably normal for that vintage. Then again it could be the black
paint on the edge/back of an element flaking off like the CZJ flektogons
do.
--

Stacey

RolandRB wrote:

Stacey wrote in message
...
RolandRB wrote:

I've got a lens and it has lots of tiny bubbles under the glass around
the circumference of the lens but not in the middle.

What lens is it?

35mm Bessamatic


It's probably normal for that vintage. Then again it could be the black
paint on the edge/back of an element flaking off like the CZJ flektogons
do.
--

Stacey

I had a large format lens - Schneider 210 (not the later apo version)
with bubbles around the edge. There was no discoloration and I could
see no effect on the images. It is likely caused by cement separation
as I recall from my research (this was about 10 years ago).

Be aware that when reselling it, it may not be worth much. So, if
you're considering buying it or just got it, think about it carefully.
If you've had it some time, about all you can do is enjoy it - that's
not so bad.

(RolandRB) wrote in message om...
I've got a lens and it has lots of tiny bubbles under the glass around
the circumference of the lens but not in the middle. Is this the
beginnings of balsam separation?

I had a large format lens - Schneider 210 (not the later apo version)
with bubbles around the edge. There was no discoloration and I could
see no effect on the images. It is likely caused by cement separation
as I recall from my research (this was about 10 years ago).

Be aware that when reselling it, it may not be worth much. So, if
you're considering buying it or just got it, think about it carefully.
If you've had it some time, about all you can do is enjoy it - that's
not so bad.

(RolandRB) wrote in message om...
I've got a lens and it has lots of tiny bubbles under the glass around
the circumference of the lens but not in the middle. Is this the
beginnings of balsam separation?

Stacey wrote:

RolandRB wrote:


Stacey wrote in message
...

RolandRB wrote:


I've got a lens and it has lots of tiny bubbles under the glass around
the circumference of the lens but not in the middle.

What lens is it?

35mm Bessamatic



It's probably normal for that vintage. Then again it could be the black
paint on the edge/back of an element flaking off like the CZJ flektogons
do.


I've seen MANY Bessamatic lenses, and the huge majority of them are in
surprisingly good condition (they seem to be especially resistant to
fungus, scratches & haze comapred to their contemporaries).
I've also never seen bubbles (though I've never come across a Lanthar
lens - also because it is a low-end 3 element design).
I also strongly suspect that it is barrel paint flaking.