Leica R 90mm f/2 Fungus Cleaning and UV Treatment
Fungus and dust inside a Summicron-R 90mm f/2. We disassemble, clean every affected optical group and finish with a UV chamber treatment that kills the spores so the fungus does not come back.
Symptoms
- Spider-web or thread-like patterns visible inside the lens
- Hazy patches on internal lens elements
- Dust accumulated inside a Leica R 90mm
- Low contrast and veiling flare in photos
Fungus inside a Summicron-R 90mm f/2 is the kind of discovery no Leica collector wants to make — fine, web-like growth on the internal elements, often accompanied by a layer of dust. Professional Leica lens fungus cleaning resolves it completely, and at a fixed price: we disassemble the lens, clean every affected surface and finish with a UV chamber treatment so the problem does not return.
The symptoms
- Thread-like or spider-web patterns visible on internal glass surfaces when you look through the lens against a bright light.
- Hazy patches, sometimes with a faint halo around them.
- Dust accumulated inside the barrel.
- In use: reduced contrast and a veiled, low-bite rendering — the opposite of what a Summicron should deliver.
What causes it
Lens fungus is a living organism. Spores are everywhere; all they need to germinate is humidity, darkness and time — a lens stored in a cupboard or camera bag for a few years provides all three. Once established, the fungus feeds on organic residues inside the lens and spreads across the glass. Internal dust accumulates through the same slow air exchange every lens experiences over decades. Neither is a defect of the Summicron-R 90mm f/2 specifically — it is simply what happens to fine optics that sit unused.
Can you fix it yourself?
You can slow it down — store the lens in a dry, ventilated place with good light — but you cannot cure it. The fungus sits on internal surfaces that are unreachable without full disassembly, and wiping the visible growth is only half the job: the invisible spores remain, and the colony regrows. On a valuable Leica R lens, home disassembly risks far more than it can gain — element centring, retaining ring finish and coating integrity are all easy to ruin.
How we repair it
A customer sent us his Summicron-R 90mm f/2 for exactly this service. Our technicians first removed all internal dust using a high-pressure air compressor. The lens was then disassembled completely, and every optical group touched by fungus was cleaned with a cloth soaked in isopropyl alcohol until no trace of the growth remained.
The final — and decisive — step was the UV chamber. The lens was treated in our ultraviolet chamber to destroy all remaining spores, including the invisible ones. This step matters: a fungus-affected lens that skips the UV treatment can see the problem reappear within a few months, whereas the UV chamber rules that possibility out entirely. After reassembly the lens passed our standard functional check and returned to its owner in like-new condition. Our full Leica service range is on our Leica repairs page.
Price and turnaround
| Service | Price |
|---|---|
| Fungus and dust cleaning + UV chamber treatment | €80 (fixed) |
| Internal cleaning | Included |
| Final test & general check | Included |
Typical turnaround is 5 working days from arrival. Return shipping anywhere in the EU is a flat €20.
Ship your lens from anywhere in the EU — diagnosis is free and every repair carries a 6-month warranty. See how it works.
Frequently asked questions
What does fungus look like inside a Leica lens?
Thin thread-like or spider-web patterns growing on an internal glass surface, sometimes surrounded by a hazy halo. Against a bright light it is clearly distinguishable from ordinary dust.
Can lens fungus come back after cleaning?
Yes — if only the visible growth is wiped away, invisible spores remain and the fungus can reappear within a few months. That is why we finish every Leica lens fungus cleaning with a UV chamber treatment that eliminates the spores.
How much does Leica lens fungus cleaning cost?
For the Summicron-R 90mm f/2 the price is €80, fixed, including full disassembly, cleaning of all affected groups, UV chamber treatment and a final functional check.
Does fungus permanently damage lens coatings?
Caught early, fungus cleans off completely. Left for years, its by-products can etch the coating. If we find permanent marks we document them honestly during the free diagnosis before any work begins.
