Black specks in UC-Hexanon

[chasdfg]

Hi all

While cleaning some of my camera gear i noticed some black specs inside my UC-hexanon. They appear to be resting on the same element. I've tried to provide pictures as to what I'm referring to, and hopefully the pictures properly illustrate the problem.

I suspect the specks are actually paint shavings from the inside barrel of the lens, which were blown into the lens when I used a blower. I have never noticed these specks before, and they definitely weren't present when I purchased the lens this year.

Any ideas where these bits may have come from?

I'm probably going to send the lens for a clean, though preliminarily the specks don't seem to affect my images.

Thanks in advance
Chas

 

[peterm1]

Hi all

While cleaning some of my camera gear i noticed some black specs inside my UC-hexanon. They appear to be resting on the same element. I've tried to provide pictures as to what I'm referring to, and hopefully the pictures properly illustrate the problem.

I suspect the specks are actually paint shavings from the inside barrel of the lens, which were blown into the lens when I used a blower. I have never noticed these specks before, and they definitely weren't present when I purchased the lens this year.

Any ideas where these bits may have come from?

I'm probably going to send the lens for a clean, though preliminarily the specks don't seem to affect my images.

Thanks in advance
Chas

I think you are most likely right about the paint. The interior of the lens barrel should be painted to reduce flare from reflected light. So it most likely has detached from the interior. That is the usual culprit for this kind of contamination - I have seen it reasonably often with older lenses. But I would not worry. This quite small amount of tiny specks will not affect image quality or lens function. If a lot of paint came off the interior I would be more worried about flare from the unpainted walls of the lens barrel when shot against bright light rather than any image degradation from the specks themselves. In this case the fix is an interior repaint more than a cleaning. I don't think I would even bother with a clean right now (maybe later) if the images in the pics are representative.

 

[chasdfg]

Hi Peter, thanks for the reply. I'll bring the lens to a technician to see where the specks may be from and weigh up cleaning it given it doesn't appear overly serious. It would be a little annoying to clean the lens and then have the specks return later if they originate from the lens itself

 

[Larry H-L]

I agree that this appears to be really minor, the specks are so small. I have a Canon EOS lens with a “big chunk” of something on an interior element. Tried hard to get it to show in an image... no luck, might as well be invisible.

 

[menos]

From the first pictures it is impossible to tell what the nature of the specks is.
The last picture looks to have a small elongated piece of debris lodged at the edge which could be a piece of antireflective paint or anything introduced through a blower blue onto the lens.

In general just a small tip regarding lenses and blower bulb any technician will tell you:
NEVER EVER use the blower bulb to "clean" the lens body - never!
Lens barrels are fitted with large enough gaps between the individual barrel components to allow for dust, dirt, debris of any kind almost as large as 1mm in some cases to enter the lens by being blown with a blower bulb.

The very best way of cleaning a lens body is by using a soft brush and a microfibre cloth always taking care not to push potential debris into the gaps between the lens barrel components.
Lenses should also be stored in a way that dust cannot easily enter such gaps on the lens barrel.

The blower bulb should be exclusively used on the front element and rear element of a lens to remove loose debris, dust etc before any further cleaning that may be necessary.

Regarding the issue you see on your lens I would first monitor if this debris does move, inspect the debris or have it inspected by a technician with proper optical equipment and experience if indeed it is loose debris.

Only then would I have the lens opened and carefully cleaned.
I understand the lens is in very nice condition.

Verify that the specks are of harmful nature before deciding to have the lens opened and cleaned (and potentially adding track marks or worse).

 

[chasdfg]

Thank you all for your replies. By way of update in case anyone comes across such an issue of their own:

I brought the lens to an experienced technician who concluded that the debris came from the aperture mechanism (paint or something along those lines). This makes sense because when I bought the lens, it was spotless and had not been used for quite a while, but after I got it I did a fair bit of stopping down and did mess about with the aperture quite a bit. The debris seems to have settled in between the elements closest to the aperture as well.

I ended up not cleaning the lens because of how minor the "issue" is and because I know where the specks likely originated from (and how they might return anyway).