Broken filter on a 70-200 f2.8 II - how to clean?

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#1
Two weeks ago I put away my almost new lens after some light use, and all was well. Nothing has happened to it during the intervening time to my knowledge (no kids or anything, bag tucked away safely), but I opened my bag today to find my filter broken with shards of glass resting on the front element.

I have no idea at all how this has happened - no sign of damage (besides the broken glass) to either the filter or lens, and filter unscrewed perfectly easily as usual. Anyone had an experience like this before?

My real question is how to clean it. I tipped it upside down which cleared 95% of the glass but there are still tiny shards all over the lens that won't shift (second attached photo), and my rocket blower has gone AWOL. Is compressed air an option? I'm terrified of doing damage to the lens itself so touching it with a cloth isn't an option, but I've never used compressed air and not sure how harsh that could be.

Any thoughts would be appreciated!
 

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Mike
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#2
have you got a clean light paintbrush just dust it off, the coating is reasonably hard. just dont start normal cleaning with a lens cloth until the shards are removed. hth mike
 
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John
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#3
bloody heck...............NEVER seen that before - thankfully

1 .. defective filter - change of temp indoors caused a stress fracture - just a guess

2...contact Canon.? BEST OPTION

3...''..but there are still tiny shards all over the lens that won't shift..'' how did you try ?

4....a DIY idea

get the lenses firmly held horizontally or even slightly downwards
vacuum cleaner with plastic nozzle
thin strip of wooly velcro around the nozzle edge
hold nozzle 2-3 mm from glass

A.. lightly tap lens edge to vibrate it
or B lightly brush lens with a pastry brush - they are really soft
or a 'fine' artists Sable brush size #2 tackling each shard one by one....................:(

2 person job really

GOOD LUCK
 
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David Williams
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#4
I once saw a method for cleaning filter that involved using a liquid that once applied turned to a pliable jelly and was peeled off - with the dust. Perhaps that might be an option.

No idea what it was called - sorry

D
 
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Steven
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#5
Well there went $50 for no reason...
As other's have said, just brush it off (w/ lens pointed down). Just be careful that you're not pushing glass into the element.

FWIW, I have never seen *any* filter shatter w/o impact of some sort.
 
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#6
I once saw a method for cleaning filter that involved using a liquid that once applied turned to a pliable jelly and was peeled off - with the dust. Perhaps that might be an option.....................No idea what it was called - sorry.............................D
it is a method discussed on hi-fi forums for removing dust from the grooves of old LPs

HTH
 
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And
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#10
my rocket blower has gone AWOL
You could buy another or see if anyone nearby has one you could borrow - I'm sure there must be someone local to you ? to see if this shifts anymore...

If anything is left, the sticky tape idea very gently applied I would think would help as you're not moving anything round so run less risk of scratching the front element.
 

Nod

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Nod (NOT Ethel!!!)
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#11
I once saw a method for cleaning filter that involved using a liquid that once applied turned to a pliable jelly and was peeled off - with the dust. Perhaps that might be an option.

No idea what it was called - sorry

D

It was called Opticlean (or similar) but seems to have vanished from the face of the Earth! I had a bottle until about 6 months ago when I discovered it had gone off in the bottle so was useless.
 
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#12
I would think the vacuum idea is best ,dyson preferably ,if you get one of the thin pointed nozzles and tape off from either side so as to leave a small powerful sector it might help .holding lense pointing down whilst doing it might help as well .if you have to resort to brushing to shift any fragments I would recommend a large soft woman's make up brush as there very soft and gentle and less likely to do damage .
Failing that it's a insurance job
 
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Julian
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#13
One of those big soft makeup brushes and an email fired off to B+W with those pictures included.
 
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gill
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#14
thanks for all the advice! In the end a combination of a makeup brush and compressed air with the help of my local camera shop broadly did the trick. There are a couple of very small scratches left over but nothing that seems to impair image quality, to my eye at least.

Unfortunately with no rocket blower, no proper vacuum (I have one of those silly roomba things and didnt think driving it over the front element would help matters) and a surprising lack of camera shops on Saturdays in NYC I couldn't do much about it until the Sunday, which was an uneasy wait. Glad I held out though rather than trying anything too experimental.

I'm packaging up the remnants of the filter and sending them off to B+W this week. Not necessarily expecting anything in return, but I'd appreciate their thoughts on what might have gone wrong given the complete lack of any visible damage to the frame of the filter. The glass is broken so cleanly along its curved edge that it doesn't look much to me like an impact, and tends to make me thing there's been a manufacturing defecit of some sort. If I find out anything interesting I'll let the board know...

thanks again!
 

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odd jim

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Jim
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#15
Next time, just turn your lens hood around and use that
 
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gill
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#16
Next time, just turn your lens hood around and use that
TBH this whole thing has made me wonder why I even use a filter on the 70-200. I still like to on my shorter lenses as the hoods only provide relatively minimal protection, but the 70-200 is so well hidden by the petal hood that I don't think the filter is really adding anything.
 

odd jim

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#17
TBH this whole thing has made me wonder why I even use a filter on the 70-200. I still like to on my shorter lenses as the hoods only provide relatively minimal protection, but the 70-200 is so well hidden by the petal hood that I don't think the filter is really adding anything.
Yeah it's useless. Tele lenses are the worst Ienses stick a UV / "protection" filter on too as when Magnification increases the quality reduction from the filter increases also.
 
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#19
Ouch. Never seen anything like this before.....Maybe contact Canon, failing that buy another lens...
 
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