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Something(?) inside my lens - what are they??

thirteen

New Member
A 150mm Sonnar (1974)- the "somethings" are not on the outside of the rear element - they are visible only when viewed at a certain angle and they catch the light - seem to "shine".
Ideas as to what they are??
 

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If they do not show up or effect the photograph, do not worry about it. Even fairly new lenses have things in them. If it was fungus, which I do not think it is, then I would have the lens cleaned and recollimated.

Steve
 
I'm not concerned about dust - in a lens this old I'd be surprised not to see some.
I just worry it might be mold - keeping my fingers crossed.
 
These particles do not strike me as a mold.
Still it may be a good time to have the lens inspected and cleaned.
Dust in older lenses can be hard to remove.
That is dust shown is removed but other dust particles are floating around and will show up after a while.
 
Possibly a dry graphite lubricant from the shutter blades?
BC

The shutter is further to the front of the lens. As much as I can judge from the posted image the material appears to sit on the inside of the rear element. If so, this is not difficult to remove/inspect given a reasonably competent camera tech. The whole rear lens assy (multiple glass elements) can be easily removed from the tube.

Wilko
(who once owned a Sonnar that needed work, and found that it was within his DIY skillset)
 
Wilko
(who once owned a Sonnar that needed work, and found that it was within his DIY skillset)


I remember you borrowed a set of tyre levers from me to prise out that rear element.
Other than that it was a smooth operation........


Paul
 
This does not look as dust . Never .
What I see are little round spots of whatever source .
Have a look here :
http://www.zeiss.de
Have a look to the CFi150 datasheet and you will find a lens diagram .

If you look at the diagram of the lenses , and as you say its inside the rear lens , it could also be some dots created by vapor or humid air .

I do believe , the real cause can only be determined , if the rear element is inspected by a specialist and then either be cleaned or the lens should be replaced .
If this is done at CARL ZEISS , if they still would give such service , would shurely cost as much as a good used lens of the same type .

Therefore , if these little spots do not affect the image , just take it as it is and don't worry about .

Jürgen
 
Thanks for all the replies.
I'm just finishing my first film thru with this lens - I'll see if there is any effect.
I did buy the lens from a camera store - it has 3 months warranty - if in doubt they can clean it. Other than these spots the lens is in great shape for its age.
 
Those look to me, to be "pinpoints" in the very outer lens multicoating. How they got there, I have no clue, maybe something corrosive to the coating got on your lens?

I'd be -very- surprised if they have any noticable effects in your final photographs. They are very small, yet, they being on the rear glass, best to test, as you are doing. If it bothers you, return the lens.

I have had John Van Stelton at Focal Point Inc, in Colorado USA, polish off old multicoatings, and reapply new multicoatings. He has to remove the glass element to be coated, it is heated up in a hyperbaric vacuum chamber. Cost was about $250US plus shipping both ways, so I doubt it's worth it, in this case.

Good Luck to You!

-Dan
 
Here is an image of how the lenses are fit together .

The SONNAR 4/150 has 5 lenses in 3 groups .
The rear lens is on the right side . I have numbered the lenses .
So , if the spots are inside the rear lens , they could then very well also be on lens 4 .

View attachment 1659

Jürgen
 
Here is an image of how the lenses are fit together .

The SONNAR 4/150 has 5 lenses in 3 groups .
The rear lens is on the right side . I have numbered the lenses .
So , if the spots are inside the rear lens , they could then very well also be on lens 4 .

View attachment 1659

Jürgen

(I am not 100% sure if the poster's lens has the exact same build as the CFi150 but let us assume it has for now)

I agree that surface #4 could hold the contamination. 4 & 5 come out in one assembly. And (by the way :mad: the diagram also shows I remembered it incorrectly, the shutter is in front of #4, so 'something' out of the shutter could have landed on the #4 lens).

Taking the #4/#5 out of the tube is an easy job so it should not cost the world to have someone inspect/clean it.

Wilko
 
Well... I probably paid over the going rate for this lens - $499 Cdn. However the camera store I bought it from is having the rear elements inspected inside and cleaned as needed plus a full lens CLA as well. If I'm not satisfied at that point I get a refund.
Thanks to everyone for your help - all the details/diagrams etc you provided sure helped when talking to the tech.
 
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