Can fungus be removed from a lens?

[c2500]

<p>I was just on ebay and saw a f1.8 85mm lens (m or earlier) that is bid up to $76. With fungus listed and obviously there. Is therea way to remove it? Just curious.</p>

<p>Thanks</p>

[JAPster]

<p>Depends on if its inside or outside the lens, and how bad it is.</p>

<p>You can clean fungus off external lens surface using this approach:</p>

<p>1) Blow away any loose dust & dirt with traditional rubber blower.</p>

<p>2) Take an old softhair brush and brush over the surface gently to remove any remaining dust. Then discard that brush so as not to transmit fungi to your other lenses.</p>

<p>3) Then use a couple of Zeiss Cleaning Napkins, available in the 'eyeglass accessories' section at your local Walmart. These are lintfree napkins pre-moistened with isopropyl alcohol solution. They will be damp, not dripping wet. Use one of those to firmly wipe over the surface of the lens having the fungus. Use somewhat more pressure than your normal lens cleaning technique. Use a circular wiping motion beginning at the center and working your way out towards the edge. At the end of each 'stroke', gently and smoothly lift the napkin off the surface, like a plane taking off.</p>

<p>I used this technique to clean lens fungus off some old lens magnifyer filters my brother gave me. I cleaned fungus off both sides and now the filters are usable again.</p>

<p>If the fungus has caused permanent damage to the multi-coating, such as etching, then i suppose the whole surface will have to be re-coated by a professional lens repair shop.</p>

<p>Likewise, if the lens fungus is on the *inside* of the lens, then someone has to dissassemble the lens to attempt a cleaning. Again, probably a job for trained and experienced lens specialists.</p>

[jpo3136b]

<p>I wouldn't be surprised if the repair bill for fixing the lens came in at $75. I would pass on the deal. You can do without that damage for about the same amount of money.</p>

[JDMvW]

<p>And in many cases, the fungus (or more properly its by-products) may actually have "etched" the glass surface so that the lens will always be "soft".</p>

[carbon_dragon]

<p>What about the old wives tale of putting the lens in the sunlight to expose it to UV? If it hasn't gone too far, could that kill the fungus?</p>

[JDMvW]

<p>I tried the "lens with foil on the back and the lens pointed into the sun" for fungus and it did not work in any very useful way--at best it <em>might</em> have killed the fungus, but it didn't do anything to make it disappear. The UV solution (sun) is supposed to work for Thorium-yellowed lenses, but I tried that without success too.</p>

[dan_mcclain]

<p>If you could win the lens for anything close to $76, I would be confident that even after a professional cleaning the cost would be fair. I had John Titterington clean a Minolta 50mm f/1.4 that had significant fungus, and the price was very reasonable, and cheaper than buying a different lens altogether. You could always email a technician and ask for an estimate, and that estimate could guide your maximum bid. </p>

<p> </p>

[jgredline]

<p>I found the best way to fix a lens I bought on ebay that was infested with fungus was to send it to Eric Hendrickson. It was a Super Tak 135F/3.5 and he charged me $30.00<br>

Came back like new.</p>

[orly_andico]

<p>I've repaired quite a number of fungus-laden lenses including a 200/4 M42 and a 200/4 K-mount. It's quite trivial for these lenses because the entire front barrel screws off, exposing the rear of the front group which is where the fungus most often is.</p>

<p>I've also fixed a Carl Zeiss Pancolar in the same way. The trick is getting at the fungus-laden element. I simply use dishwashing liquid applied with a (clean!) fingertip. Gets the fungus right off. I've never seen a case where the glass got etched by the fungus.</p>

<p>$76 for an 85mm is dirt-cheap. I'd grab it in a second and clean it myself.</p>

[stemked]

<p>Regarding UV light killing fungus:<br>

UV light itself generally has low penetrating power. In experiments I do every year with my microbiology students even a very thin film of clear plastic is enough to block even intense UV light. UV has very little ability to kill bacteria that are normally pretty sensitive to UV light in these experiments. So I'm not sure why exposing lenses to light kills fungus, maybe it is that low levels of UV light are killing the cells, maybe it is removing moisture, I'm not sure. I might try a slight modification of the test this year with lenses, we'll see if I can pull it off.</p>

[fotografya]

<p>Will the anti-fungal antibiotics work? Just in case... :P</p>

[User_502260]

<p>Last year I bought an 85/1.8 Canon FL for $10 from a bargain bin at a camera show. It had what looked like some fungus, some other assorted kinds of dirt and a bent filter rim. A trip to Essex Camera Service was exactly what the lens needed. I really enjoy using it. Not every fungus story has a happy ending but I have had my best luck with Canon lenses.</p>

[brian_quinn2]

<p>Antibiotics will not work against fungus.</p>

[astral]

<p>An acquaintance who I know has ample qualifications in optics once remarked that hydrogen peroxide will normally eradicate fungus. While I cannot substantiate that, since I've never had an affected lens, I might try it some day. Clearly it cannot restore glass that has been etched. I'll email him for corroboration . . . .</p>