condensation or fungus?

JC · Joined: 02 Jul 2013 Posts: 25 Location: U.S.

Bought this lens on a gamble, advertised as a little bit of fungus, but now that I have the lens, not sure this is fungus. It looks more like dried water droplets or similar. They are both on a single piece of glass behind the aperture, which is pretty darn dusty.

in this picture the whole lens element looks fogged, but it's not.

either way, they are small and very peripheral, and not, I think, a big deal.

so, fungus or condensation?

philslizzy · Joined: 07 Aug 2012 Posts: 4749 Location: Cheshire, England

To my eye it looks like its either chipped glass or cement is coming apart from the elements. Defo not fungus. Is there physical damage to the barrel near the mark? I've seen this kind of thing on lenses where the filter mount is bent after a drop.

JC · Joined: 02 Jul 2013 Posts: 25 Location: U.S.

iangreenhalgh1 · Expire: 2014-01-07

Separation I think, it usually starts at the edge like that.

JC · Joined: 02 Jul 2013 Posts: 25 Location: U.S.

ZoneV · Expire: 2011-12-02

Uh, the Olympus 90mm/2 Macro!
Does not look like delamination to me, more like fungus, or probbaly some kind of other dirt.

iangreenhalgh1 · Expire: 2014-01-07

Hmm, so no cemented elements. Then I would say it is probably what is left behind after some liquid has dried. Definitely doesn't look like any fungus I've seen before.

JC · Joined: 02 Jul 2013 Posts: 25 Location: U.S.

literally the day after my last post I had to pack up all my gear and move, and so I didn't have much chance to use my new lens.
This is probably not the best test of the lens, but this is what I've done with it recently.

Olympus 90mm macro, plus Olympus OM 65-116 Variable Extension Tube, on the OM-D E-M5. Field of view is <1cm.
Any flaws in the image are from my impromptu set up, quick focus stack, and flashlight lighting system.

I think I gambled and got a great deal. Pretty sure now that the splotches are just condensation rings.

Now I need to start a hunt for the 20mm macro.

leemik · Joined: 21 Feb 2011 Posts: 107 Location: Quincy, MA

I think I have the same thing on a Konica Hexanon 57/1.2 .. on my lens it's near the middle of the glass not the edges. It's a round circular bullseye like defect that looks like yours. Hard to photograph. I can see 3 very faint ones near it as well when I look at the lens at an angle. Not sure if it's just a reflection of the defect or 3 other less apparent defects.

I never could figure out what it was. It doesn't seem to affect pictures.. heck I think the metal shroud on the rear element has more of an effect Smile

--mike

Gardener · Joined: 22 Sep 2013 Posts: 950 Location: USA

Could be a water spot. If you are not on full frame I would not worry about it.

Gerald · Joined: 25 Mar 2014 Posts: 1196 Location: Brazil

Bad news: it appears to be fungus. Sad

Good news: the amount is too little to affect the picture. Smile