What is this in my lens?

[cheap]

Hello all,

I recently purchased a 20/3.5 Pen F lens at a large auction site. Looking from the rear of the lens I was saddened to find a big spot. I have seen dust-spots before and also fungus. I don't know what is going on in this lens at all! The flaw is inside the lens, towards the rear elements I think.

The lens is on a light-box, viewed from rear. I photographed it with a Zuiko 50/3.5 Macro plus 25mm extension ring:

The flaw also seems reflective, here it is again viewed from the rear of the lens this time looking out a window:

You can see the window scene reflected in the flaw (close-up of above image):

Does anybody know what is going on here? I have no idea if the lens is salvageable or not...

Thankyou, Bruce.

 

[hans voralberg]

Looks weird, sort of like a chip?

 

[cheap]

Looks weird, sort of like a chip?

I hope not; the flaw is inside the lens so I don't know how it might get chipped there...

 

[Sonnar Brian]

It looks like a chip, or fracture in the glass. I have one lens with a fracture (crack in glass) on an internal element.

If you can return it, do so unless it was cheap. If you keep it, shoot with it and find out the effect on the shots.

 

[squinza]

Seems quite large. It's not a bubble, isn't it?

 

[cheap]

Seems quite large. It's not a bubble, isn't it?

I thought it might be a bubble, but it seems kind of large--more like huge! One wonders how a bubble of that size would escape the notice of quality control. The JCII sticker is long gone if it ever got one!

 

[Steve M.]

I haven't seen anything like that before, but it does appear to be a chip possibly. The only thing to do is shoot it w/ a cheap roll of film and get a quick CD at Walgreens or somewhere and see. I'm sure it will have some effect on the photos but unless that particular area is of prime importance it may be negligible. One little pass w/ the clone tool if you do digital processing will probably fix it.

 

[cheap]

Here's another view of the flaw. Maddeningly, it looks different as you stop down to different apertures (when photographing it):

 

[cheap]

If you can return it, do so unless it was cheap. If you keep it, shoot with it and find out the effect on the shots.

Despite my screen-name this lens was one of the more expensive I have ever bought secondhand (160 euro). Ouch.

We have just put in a film to be developed, but didn't really test the lens out for the flaw per se.

The flaw is at the 7 O'Clock position. As the Pen cameras default to vertical framing I expect that it will be in the frame somewhere.

 

[sevo]

Looks like a tiny particle that did not dissolve in the molten glass, and created a strain at which the glass chipped creating a tiny crater. Stuff like that happens - but it probably chipped the lens decades ago. If the seller did not describe it, it is time for a return/refund...

Sevo

 

[Roberto V.]

Maybe a drop of oil? I'd hope it was oil rather than a chip.