Not for the faint of heart: 55-200mm partial tear down

[Sebastien Guyader]

I live in a tropical, with a quite humid climate, and my apartment is particularly humid. As a result, fungus grew on my 2 lenses' rear elements (55-200mm zoom and 23mm f/1.4). Ok, some of you guy will tell me I should have protected my lenses, but I just thought it would not happen on quality glass... Silly me, lesson learned.

Living on an island in the middle of the Caribbean, sending my lenses for cleaning would cost me quite a lot of money because of the cost of overseas shipping, added to the cost of cleaning by a professional (I don't know if there are any local professionals, but I wouldn't trust them more than myself).

So, I decided I'd try to disassemble the rear elements and try to clean the fungus, being inspired by some tutorials and videos I found on the internet. Starting with the 55-200, using some information from the guys at Lens Rentals who did the disassembly. Then I saw with horror that not only the rear element was affected, but also the third element inside the zoom. Getting to rear element and removing it for cleaning was not too hard, but I didn't dare going deeper (actually the Lens Rentals tear-down page didn't give me enough step-by-step details to go further. But I was able to use a cotton swab and put some ammonia/H2O2 mixture on the fungus spot on the middle zoom element (which is behind a second lens element) and prayed it would work.

Then I cleaned the mixture, used an air blower to dry the glass and remove any dust/lint left over, and proceeded to reassemble the zoom.


Half way of reassembly

Sorry, it's the only image I took of the process. But I'm proud to say that the lens is cleaner. There's still some traces of fungus on the rear element, I should have let it soak longer in the cleaning mixture, but now I know I can do it and if I need, I'll clean it again more thoroughly. And I'm even prouder to say that the lens is 100% working!

Now the 23mm f/1.4 is waiting for its turn...

 

[third son]

You have some guts! Realistically it was all you could do with the circumstances and it turned out very well indeed.

Nicely done!

 

[Sebastien Guyader]

Thanks Paul. In fact I was also encouraged by the success of disassembling my cell phone to replace a cracked LCD screen. It was also a matter of removing parts, proceeding in order, disconnecting some ribbon cables... and putting everything back together.

 

[Lettermanian]

You are very brave I haven't researched the idea, but would constructing some kind of lens storage box with a UV light inside help stop the growth at all?

 

[KFo]

That’s great! And I thought that DIY ethic had gone away.

--
Opted into the Fuji X system big time. Like to travel light and shot quick; that's why I also have a Ricoh GR....
Perfect is the enemy of good!

 

[Sebastien Guyader]

You are very brave I haven't researched the idea, but would constructing some kind of lens storage box with a UV light inside help stop the growth at all?

I bought a couple small boxes with silical gel in them (something like 100g of product) and let them in my small camera bag along the X-T2 and the 2 lenses. But guess what... The air is so humid here that just overnight the silicagel gets saturated with humidity.

So yes, I'll by a small air-tight box (probably some sort of tupperware) and put 5 silicagel boxes, it should help. Regarding UV light, I wouldn't use it permanently, as I'm afraid UV rays could damage some parts of the lenses in the long term. But I'll definitely use UV light for short periods of time.

 

[rgleich]

Suggestion -

Maybe try one of the smaller or mid-size Pelican air-tight cases for long-term storage of lenses when you're not using them, cut the foam to fit your lenses. I know from experience that they're GREAT for mechanical protection, and they have gasketed cases that should seal-out the moisture. THEN put some large Silica-Gel packets or canisters inside with your lenses.

Guess it's part of the "price you pay" for living in Paradise?

 

[rwbaron]

My hat is off to you sir as you are a brave man.

Good work.

Bob

 

[rwbaron]

Suggestion -

Maybe try one of the smaller or mid-size Pelican air-tight cases for long-term storage of lenses when you're not using them, cut the foam to fit your lenses. I know from experience that they're GREAT for mechanical protection, and they have gasketed cases that should seal-out the moisture. THEN put some large Silica-Gel packets or canisters inside with your lenses.

Guess it's part of the "price you pay" for living in Paradise?

Exactly what I was going to suggest.

When flying with those, if you have the pressure relief closed, you have to open it upon landing as the top of the case is sucked in from the vacuum created. Very effective seal and I would think with silica gel in the case the OP should be fine.

BTW you can reuse silica gel by baking it at low temps in the oven.

Bob

 

[Sebastien Guyader]

Yes I know I can dry off the silica gel in the oven, I did it with the small packet I have. Before investing in a solid, expensive box, I'll try my chance with air tight kitchen boxes and see how long it takes before the silica gel needs to be baked.