Nigel Grantham
Member

Last year I have bought two new binoculars, a Leica Ultravid 7x42 for myself and a Zeiss SF 8x32 for my wife. Looking down the barrels of both objective lenses on purchase they were perfect. A few months later a visible small white hair/thread appeared in one barrel of the SFs, not on the surface of the objectives but clearly on one of the internal lenses. Now looking at my Leica's today I can see exactly the same thing, it was not present just a few days ago.
Although aesthetically annoying this seemingly doesn't effect the view in any way, so I'm probably not going to send them back (although not great I suppose if I ever resell them). But I am curious how this happens? Would the hair be already inside when the binocular was assembled in the factory and over time has somehow moved into the centre of the barrel and become visible? Or has it somehow entered during use, which would be concerning with regards to how well sealed both binoculars are? I'm surprised this has occurred in two reputable brands and wonder how common an occurrence this is? I've not encountered it in previous binoculars I've owned. How many other people have had this happen?
Although aesthetically annoying this seemingly doesn't effect the view in any way, so I'm probably not going to send them back (although not great I suppose if I ever resell them). But I am curious how this happens? Would the hair be already inside when the binocular was assembled in the factory and over time has somehow moved into the centre of the barrel and become visible? Or has it somehow entered during use, which would be concerning with regards to how well sealed both binoculars are? I'm surprised this has occurred in two reputable brands and wonder how common an occurrence this is? I've not encountered it in previous binoculars I've owned. How many other people have had this happen?