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Advice on Removing Fungus from canon 400mm f/2.8l ef is usm lens

Started 2 months ago | Questions
b3 New Member • Posts: 1
Advice on Removing Fungus from canon 400mm f/2.8l ef is usm lens

In 2010 I bought a CANON 400MM F/2.8L EF IS USM LENS. It now has developed fungus in the lens. I want to disassemble and clean it if possible but I can't find any instructions or tools. I would gladly send it to someone for professional cleaning but I understand Canon quit servicing this model in 2017. Any suggestions are appreciated. I am looking for someone else to clean it or for links to tools and DIY suggestions. I have seen many videos on cleaning smaller lenses but I can't even find a spanner wrench that would fit this lens.

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John_Hoffman
John_Hoffman Senior Member • Posts: 2,245
Re: Advice on Removing Fungus from canon 400mm f/2.8l ef is usm lens

I have never personally disassembled, but I have read that some require special tooling and adjustments to reassemble correctly.

You might try a third-party repair service like Midwest camera. Fungus can actually destroy the lens coating.

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John Hoffman
Conway, NH

 John_Hoffman's gear list:John_Hoffman's gear list
Canon EOS-1D X Mark III Canon EF 100mm F2.8L Macro IS USM Canon EF 70-200mm F2.8L IS II USM Canon EF 8-15mm f/4L Fisheye USM Canon EF 70-300mm f/4-5.6L IS USM +10 more
BirdShooter7 Veteran Member • Posts: 9,134
Re: Advice on Removing Fungus from canon 400mm f/2.8l ef is usm lens

I took one apart years ago and suggest both bothering unless the fungus is really having an impact on your image quality and in that case I’d try a third party repair shop if you can find one.  Even then it’s probably not worth the cost.

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Some of my bird photos can be viewed here: https://www.flickr.com/photos/gregsbirds/

MarshallG
MarshallG Veteran Member • Posts: 8,968
Re: Advice on Removing Fungus from canon 400mm f/2.8l ef is usm lens

Ouch. Why not call Canon and ask if they'll service it anyway? Can't hurt to ask.

 MarshallG's gear list:MarshallG's gear list
Canon EOS R5 Canon EF 50mm F1.4 USM Canon EF 85mm F1.8 USM Canon EF 16-35mm F2.8L II USM Canon Extender EF 1.4x II +4 more
BirdShooter7 Veteran Member • Posts: 9,134
Re: Advice on Removing Fungus from canon 400mm f/2.8l ef is usm lens

MarshallG wrote:

Ouch. Why not call Canon and ask if they'll service it anyway? Can't hurt to ask.

Definitely worth a shot.  I did several years ago and they provided me with a list of potential third party repair shops to try.

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Some of my bird photos can be viewed here: https://www.flickr.com/photos/gregsbirds/

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