Agrrr... AF Nikkor 50f/1.4 delamination

[p.giannakis]

Ahgrr.. this is the second AF Nikkor 50f/1.4 that develops delamination.

The first one I bought it cheap as there was something that looked like a tiny speck of dust which on closer inspection was the beginning of element separation. Within 6-7 years it grew to cover almost a quarter of the lens and gave it away.

I bough this one back in 2015 and it was in pristine condition. Three/four years ago it started again as a small speck of dust but it looked very usable until recently. I last used it during my Easter holidays and was ok.

Today I noticed this mess! Is this a common issue with the AF Nikkor 50f/1.4? The plain 1.8 version I have has been beaten to death and looks good.

 

[PRJ]

According to the diagram I just looked at the front element is by itself, so the cement isn't failing since there isn't any to fail. I'd guess that is some type of lubricant. Do you store your lenses facing down? Is it hot where you are? Could explain it. If so it would be pretty simple to remove the front element and clean it. It will probably come back though unless the lubricant is replaced.

Hope that helps you.

 

[p.giannakis]

According to the diagram I just looked at the front element is by itself, so the cement isn't failing since there isn't any to fail. I'd guess that is some type of lubricant. Do you store your lenses facing down? Is it hot where you are? Could explain it. If so it would be pretty simple to remove the front element and clean it. It will probably come back though unless the lubricant is replaced.

Hope that helps you.

You are right - It is not delamination.
I took the front elements apart but unfortunately the second and third element are enclosed within a plastic case.


Unlike other nikkor, this cannot be opened. The plastic cup at the end rotates freely (after having added a bit of acetone on the holes) but it doesn't unscrew. It is difficult to describe it but it looks like it is bent around the lens element to keep it in place.

When I rotate the ring I can see that something has seeped between the elements and stained them both.


I turned then to coincide and put it back together again.

 

[Sonnar Brian]

I have an original AF-Nikkor 50/1.4, late 1980s first generation- and it is perfect.

Yours- looks like oil, "MAYBE???" plastic outgassing???

It looks nasty, but how are the pictures with it?

 

[p.giannakis]

I have an original AF-Nikkor 50/1.4, late 1980s first generation- and it is perfect.

Yours- looks like oil, "MAYBE???" plastic outgassing???

It looks nasty, but how are the pictures with it?

The plastic tube feels dry, no oil anywhere. My only guess is that whatever they used for thread lock might have started evaporating in heat.
I cant see anything on the pictures so far. I might need to shoot the lens stopped down to see if it appear then.