Did you ever see such a phenomenon at a Nikkor?

[Peter_S]

I already disassembled the lens and removed the front element to see what's going on.
It's at the border of the two elements behind the front element. They are not cemented at this K type lens.

I took the whole front group out and removed the first lens. The two lenses remaining show this phenomenon.
I couldn't get apart this two lenses.
Any ideas?
Thanks for your replies
Peter

[richardHaw]

I already disassembled the lens and removed the front element to see what's going on.
It's at the border of the two elements behind the front element. They are not cemented at this K type lens.

I took the whole front group out and removed the first lens. The two lenses remaining show this phenomenon.
I couldn't get apart this two lenses.
Any ideas?
Thanks for your replies
Peter

looks like Scheideritis 

don't worry, it's largely harmless
i have a 28mm that I soaked in water until the ink used to blacken the edges of the lens is gone then I used an acrylic flat black to paint the edges back. a repairman told me that a kind of ink is used for this and NOT paint, that is why it is applied thin and water-soluble. the Japanese word he used is "sumi" and he said that it's the same ting used in calligraphy but of a slightly different type.

[Matthew Currie]

My old 85/1.8 from about 1970 has this issue.  It seems to have had no effect on the lens except to make it irresistibly cheap.

[Peter_S]

thanks, sounds good.
I got this lens also nearly for nothing togehter with 50 1.4 auto sc.
The auto sc had a bent filter ring because somebody dropped it.
I disassembled both this weekend, cleaned the helicoids, modified to AI and added a chip.
The only thing I could not manage is this phenomenon at the K lens.
Beside of this visible flaws the lenses look like new.

But ok, thanks a lot for your advice 😀

[Hugh_3170]

In the second world war the British collected up thousands of cameras from the public for war use.  (Apparently supplies from Germany and Japan were ever so hard to get back then, LOL.)

Many of these cameras had lenses with chips and scratches and thick black India ink was frequently applied to these defects to minimise the effects of such damage.

looks like Scheideritis 

don't worry, it's largely harmless
i have a 28mm that I soaked in water until the ink used to blacken the edges of the lens is gone then I used an acrylic flat black to paint the edges back. a repairman told me that a kind of ink is used for this and NOT paint, that is why it is applied thin and water-soluble. the Japanese word he used is "sumi" and he said that it's the same ting used in calligraphy but of a slightly different type.

[MFloyd]

I used to have a dent in my Zeiss Planar 80mm f/2.8; Hasselblad repaired it with a fill of Chinese ink, which worked out perfectly.

[Peter_S]

it's not a chip or scratch, it seems to be where the second and third element touch each other at the border.
They are not cemented, maybe only at the border??
I don't know. Front lens is in perfect condition, optical performance is as new.
Nevertheless it bothers me a bit at this nice lens, all the rest looks like new.

[Roland Vink]

This does not look like separation between cemented elements. The bubbles are only around the edge of the elements, it is probably the paint used to blacken the lens edges (for suppressing internal reflections) that is starting to blister and pull away from the glass. Apart from the cosmetic appearance, the only effect is the increased chance of internal reflections and flare. I guess the only way to fix this is to disassemble the lens and repaint the lens edges as Rick mentioned. I have some lenses like this to a lesser degree, so this is not uncommon.

[Peter_S]

thanks a lot for your replies.
I took out the front group of the lens and removed the first element. I didn't get in the first trial the following two lenses apart. If there's only a bit more internal flare I let it like this. Every disassemble has the risk of dust and scratches.....

[Henry45]

I have a used 35mm 1.4 ais that has developed the same problem since I acquired it 2 years ago.  I store the lens in a sealed bag with silica gel, and if wonder whether the latter has caused the black paint on the edges of the elements to evaporate?  Has your lens also been stored with desiccant?

[Erik Lund]

That is very difficult to to know when you don't know the history of the lens...


It could have been exposed to all sorts of conditions.


Sell it and get a better sample or live with it

[David H. Hartman]

I have a used 35mm 1.4 ais that has developed the same problem since I acquired it 2 years ago.  I store the lens in a sealed bag with silica gel, and if wonder whether the latter has caused the black paint on the edges of the elements to evaporate?  Has your lens also been stored with desiccant?

I'd be concerned about the desiccant. Silica gel can be baked in a oven at 210 to 250 to drive the water out of it. Beads will frequently have a few indicators that turn blue when they have absorbed water and are no longer a effective as a desiccant. Bake them at very low temperature and they are ready for use again.

Storing a lens in a sealed plastic bag with moisture I would think is more harmful than good. I live in So. California where we have hot dry summers and cool moist winters but our forced hot air heating and air conditioning keeps our houses quite dry all year round.

I save silica gel beads in a big jar for use where moisture might be a problem and I eat the crushed granular silica gel packets.  

I don't find the granular silica gel useful compared to the dust free silica gel beads.

Dave Hartman

The crushed silica gel is good for drying flowers and can be bought or saved for the purpose.