Fungus isn’t an issue most of us have to deal with when using modern glass. It comes pretty well sealed, and it’s usually not old enough to let major fungus issues develop yet. But, if you’re buying older lenses at the rate Mathieu Stern does, it becomes inevitable. Usually, you’ve got a couple of options. The first is to simply sell it on and find another. But the more productive route is to just give it a good clean.
In this video, Mathieu shows us how to open it up and get to those elements. Then, an easy way to get them clean using soap and water, then vinegar. Finally, how to reassemble things so that everything works as intended.