[DeadJohn]

As Tom said, there are so many stories that the truth is fuzzy. Lens fungus seems to need darkness plus high humidity to thrive. I keep seldom-used lenses in an airtight container with a rechargeable dry pack to control humidity.

Fungus spores are everywhere. Store a lens in the wrong conditions and fungus might grow.

[Lloydy]

One more thing regarding fungus.

There are so many stories, myths, hear-says, etc. floating about the web that it's hard to tell what the actual truth is.

From MY experience (I've been repairing lenses for a few years now, but of course my opinions could be totally wrong) the lens fungus has not had any detrimental health effects on me so I assume they are safe to humans in the small doses that one comes across in handling infected lenses. Whilst fungus spores exist everywhere, the specific type that affects lenses (more specifically, the type that likes to feast on the organic residue on the lens) may not be so common. How easily these spores gets transported from one lens to another is unknown. Once the fungus has been killed off by fungicide, UV radiation, etc. it should not grow any further (well, it's dead). To avoid growth of fungus, always store your lens in a cool, dry place with plenty of airflow. Cupboards, boxes, camera bags, or any other enclosed areas should be avoided. If you live in a humid climate, then use of a specialised dry box may be a good idea. Don't keep your lens stored away for long periods of time. Take it out regularly and use it to give it fresh air.

I agree with Tom's experience. I've never had fungus transfer from a lens to a camera - to another lens. If I get a lens that's affected then I leave it on a window ledge without the caps, and no filters, for a few weeks before I clean it. And for that I use cold cream, plaster it on the elements and leave it an hour or so and then wash it off with soapy water, then lens cleaning fluid. A lot of people recommend alcohol to clean elements but I've had alcohol remove the black paint from around the edge of elements so I now always start with the benign option of cold cream. And I've had great success with it, you just have to be a bit patient and let it work.

Of course, if the fungus has been left for a long time and it has secreted the acid deposits then nothing is going to save the glass. The two elements below have had the fungus cleaned off with cold cream but the acid etching is deep in the glass, I can feel it with my fingers on the left element.
The left element is ruined, both sides are deeply etched and you can clearly see the filamental pattern in places. The element on the right was from a different lens and has small portions of etching, the crescent is particularly deep.
But this was the only element in both lenses ( Left element -Minolta Rokkor 135 / 2.8 Right element Olympus Zuiko 135 / 3.5 ) that was affected, every other element was spotless. Which makes me much more relaxed about the threat of rampant fungus from an infected lens.

[IMG]
fungused elements par David Lloyd, on ipernity[/IMG]

If a lens has light fungus then I'll kill it with sunlight / UV and then use it and store it with the rest of my lenses - in partitioned, non airtight, storage boxes that are translucent. I always store them without caps, let the air circulate and the light in. I also run a dehumidifier where I keep my lenses. In a climate where it has been known to be cold and damp I haven't had any lenses in a collection of around 150 and 40 cameras that have developed fungus, or got worse if they already have it.

[malenisjaj]

Hi,
I didn't want to open new thread, so here I am,
I just got offer: Carl Zeiss Jena (DDR Pancolar MC electric) 50/1.8 (m42) with Praktica for $50. Problem is that on the rear side is something strange. The owner says it can't be cleaned from the outside, so it must be from the inside of the lens. What do you think it is and would it be a good buy or should I leave it? Other from that, the glass is clear with no scratches.

[malenisjaj]

Anyone?

[manntax]

Hi, I didn't want to open new thread, so here I am, I just got offer: Carl Zeiss Jena (DDR Pancolar MC electric) 50/1.8 (m42) with Praktica for $50. Problem is that on the rear side is something strange. The owner says it can't be cleaned from the outside, so it must be from the inside of the lens. What do you think it is and would it be a good buy or should I leave it? Other from that, the glass is clear with no scratches.

By the look of it from your photo ( which isn't perfect ) I would say there are some fine scratches + some spots which might be just sort of damage to the coating ? Anyway if the lens is otherwise clean and bright when looked through the glass against some bright lamp or light source AND it renders sharp shots from wide open ! - then I would buy it for these kind of money, probably bargain down to $35-40 due to these faults. I already own other two Zeiss lenses (35 and 135) and would love to get the pancolar too - PLUS I already own an M42-to-K-mount adapter - so no extra spendings for me to use the check the lens.. I had briefly tested one of those pancolars and the quality of rendering is indeed out of this world - sharp too , but I know there are many versions with slight changes to both the optical formula and mechanical construction so not sure how your one would be scoring.

[malenisjaj]

Photo was shoot by the owner of that lens.Unfortunately, I don't have chance to test it with my camera since it's too far from me. I have to think what to do. Thank you.

[manntax]

Photo us provided by the owner of that lens.Unfortunately, I don't have chance to test it with my camera since it's too far from me. I have to think what to do. Thank you.

In this case I would rather pass on it - you might run into more problems with this lens. The spots looks like would clean off easily but there appears to be some scratches as well, so in such case that you cannot test and see the lens in person - I suggest to leave it to somebody who can.

[malenisjaj]

I'll do that. Thank you all. (: