Ignoring all the arguments about the effect of dust inside a lens, can someone please tell me which lens is prone to quite a lot of dust on the inside.The lens I am thinking of has been talked about quite abit here, but I can't find the thread.Is it the 17-55 2.8 IS?

i think it's those push/pull zooms...white.porthackingwrote:Ignoring all the arguments about the effect of dust inside a lens, can someone please tell me which lens is prone to quite a lot of dust on the inside.The lens I am thinking of has been talked about quite abit here, but I can't find the thread.Is it the 17-55 2.8 IS?

The push-pulls are more prone to this as they move some volume of air. I imagine the 100-400 is one such lens.

to answer directlyyes... 17-55..about 1/2 get it...as I recall===========and YES to the 100-400...some get it in that one too

Are either of the 24-40 2.8 L and the 70-200 2.8L IS Push-pull lenses?

What is Canon's view if you are one of the 50% that get the dust inside the lens? Do they replace it?

porthackingwrote:Are either of the 24-70 2.8 L and the 70-200 2.8L IS Push-pull lenses?No, but the 24-70 extends with zoom, so it draws as much air as a push/pull design would.

porthackingwrote:What is Canon's view if you are one of the 50% that get the dust inside the lens? Do they replace it?No. It's a dusty world out there and getting dust inside a lens is inevitable. It is not a flaw nor a warranty issue. They'll clean it for you if you ask, but they're likely to charge for that.No lens manufacturer has any different policy.

It seems the seal around the front element is faulty/inadequate on some copies of the 17-55IS. There was a guy who took his own lens apart, cleaned it, and posted pics of the whole process on one of the photography boards.One solution if you really want to keep the dust out is to keep a filter on the lens. Not trying to start the whole filter debate here, just noting that in this particular case the filter has a purpose beyond simply preventing scratches on the front element's surface.

no text

Mine had the problem. I sent it back to Canon, and they cleaned it. The tech said the "dust" was caused by an interior gasket that was corroding. So the problem isn't that the lens isn't sealed.I got the lens back three months ago. Dust has started to appear inside the lens again.