lens cleaning

supermangyan

any of you guys know how to dismantle a Canon EF 24-85 lens? I want to open it so I can try & clean the fungus, I don't know how long the fungus has been there but I'd love to give it a go. it's a good lens that a friend bought from someone & I've been using it ever since. I find it very sharp but the fungus has been quite obvious when used on long exposures.
anyone who knows how to do this? thanks!

pixbyjohn

Give zerohamster a shout or pm, he may be able to help you.

supermangyan

i will!! thanks!

magicbastarder

i would strongly counsel against trying it yourself unless you're willing to risk trashing the lens.

Thecageyone

Here's where I come across as a complete n00b - how do you know if a lens is suffering fungus invasion? I can tell when there's trapped dust [which usually does not affect the images] But fungus? i hear it all the time, and maybe I've been lucky? [I've owned lenses over 20yrs old with no trouble] - But I've never witnessed fungus infection. I imagine it's, well, some gunk, inside the lens, trapped between the elements?

If so, I'd not go near it, you'd have to move glass? Pro-job that.

zerohamster

@Thecageyone:
fungus looks different to dust in that it usually grows in patterns or branches as such (google "lens fungus" and you will see plenty of different examples).
If you take care of your gear and make sure it is stored in a dry area preferably with silica gel (absorbs moisture and most commonly found in new shoes at shops) then you should never have problems with fungus as it grows in warm, dark and damp conditions the fastest and once inside a lens can cause massive damage if left alone.
The main problem is that some types of fungus are acidic etch into the lens coating very fast and even if cleaned have ruined that element.
Id say you are lucky if you have never seen fungus on a lens, you must take good care of your gear.

@Supermangyan: Ill reply to your Pm now.

Heebie

If you know what fungi look like.. (see photos mentioned above) you can easily tell the difference between then and dust.
A fungus problem will also strip the coatings off the lens, leaving it permanently altered (some would say ruined..but some might like the effects that happen due to the areas where the coatings have been eaten away.)

Rainbowsend

I have heard that regular exposure to sunlight helps in the fight against fungus, I regularly leave the lenses on a bright windowsill for a "sun bathe" and have had no problems with fungus, I had one very old lens that had a touch of it and it seemed to disappear after a time on the windowsill, (the fungus not the lens )

zerohamster

Rainbowsend wrote: »

I have heard that regular exposure to sunlight helps in the fight against fungus, I regularly leave the lenses on a bright windowsill for a "sun bathe" and have had no problems with fungus, I had one very old lens that had a touch of it and it seemed to disappear after a time on the windowsill, (the fungus not the lens )

UV light kills fungus so it will only help if there is fungus in the lens, otherwise you just stand to heat up the internals of the lens and possibly evaporate lubricant or worse still cause focused sunlight to light something on fire if both caps are off. Get yourself some silica gel sachets and put one in your cam bag and lens bags etc...
it absorbs moisture having the dual effect of halting the growth of fungus and also helping to prevent condensation damage when the camera goes from a cold to warm place.
Be carefull leaving them out regularly as bright warm sun might damage the lens rather then do any good, best just to store them in a dry place and prevent moisture to prolong their life.
sunlight will also only kill the fungus but wont remove it so Id say you got lucky there with that fungus dissapearing.