100-400 4.5-5.6 troubleshooting, paper between lens layers?

[John_Arneson]

Anyone seen this before? Still seems to shoot fine even around what appears to be paper between the lens layers... unfortunately discovered on vacation/photo shoot 😉  Any idea how problematic it will be to repair ($-$$$)...

[MikeSowsun · Accepted solution]

Canon actually uses pieces of black tape inside many of their lenses. My guess is a piece of tape has come loose and found it’s way to the front of the lens. 

[wq9nsc]

Does that have a screw on filter with the debris caught between the filter and the lens glass?

Rodger

[John_Arneson]

I wish! 😉 Unfortunately it's between the internal glass layers. 

[shadowsports]

Greetings ,

I'm on my phone right now so I can't get a good look. I do know that my 100-400 doesn't have any paper shavings.  I'll look at it more closely in the morning.. Any idea how whatever it is got in there?

[JFG]

How long have you had that lens?  If the piece is ingrained in the glass, then quality control had a blind inspector!  Did it come like that new or did you purchase it used?  It is hard to believe that could happen.

[shadowsports]

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@JFG wrote:

How long have you had that lens?  If the piece is ingrained in the glass, then quality control had a blind inspector!  Did it come like that new or did you purchase it used?  It is hard to believe that could happen.

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Yes.  All of this  ??  We are going to need the back story on this. That is one of the most bizarre things I've seen.   

[ebiggs1]

It is  a flaw for sure. The question now becomes what do you do? If it doesn't impact the photos perhaps you forget about. If on the other hand you want it fixed it will need to go to Canon. Now the question is, is it still under warranty or is the dime on you? Call Canon and set up a C&C.

[amfoto1]

This appears to be "separation".

Some lens elements are "glued" together to form a "group". Sometimes the glue between them fails for one reason or another. It ends up looking a lot like this. If this is the case, AFAIK the only solution is to replace the group. 

Another possibility is that some moisture got into the lens and dripped onto the surface of an element, leaving a "deposit" of minerals or whatever. Think of the water spots you see on glass when it's left to dry, for example. This might be more easily fixed... just a good cleaning, although disassembly of the lens would still be needed.

The thing to do is get it into Canon USA repair dept. and have them look at it. They can give you a repair estimate. I can't.

NOTE: If this is the earlier version of the lens, with the push/pull zoom, I recommend you call Canon first to be sure they still work on that version. It's been out of production for almost 10 years now. If it's the "II" version, should be no problem getting work done on it.

***********

Alan Myers
San Jose, Calif., USA
"Walk softly and carry a big lens."
GEAR: 5DII, 7DII (x2), 7D(x2), EOS M5, some other cameras, various lenses & accessories
FLICKR

[normadel]

This isn't a random mineral deposit. It is a chunk of something. Doesn't look like it could be adhesive from in between elements.  Could a push-pull zoom have sucked in a big piece of something like this?

[MikeSowsun · Accepted solution]

Canon actually uses pieces of black tape inside many of their lenses. My guess is a piece of tape has come loose and found it’s way to the front of the lens.