Film Under Binocular Lens'

[Thirteenth Star]

A pair of binocs I own has a film that looks something like oil under the ocular lens', and another pair of binocs has a similar film under both the ocular and objective lens'. What the dickens is this stuff, and how do I get rid of it, save breaking apart my binoculars?

And yes, I'm considering purchasing nitrogen filled binocs.

 

[BlueyM]

Have the binoculars been left in the sun or on the dash of a car during the day, and been overheated?

A gas can be exuded from the casing of the interior, particularly in the cheaper brands, which will condense again after cooling off, and be noticeable on the lens.

I think the only way to clean them will be to dismantle them if this is the culprit. A specialist shop should do this if you are unsure how to go about it.

Good quality optics should be treated kindly whenever possible.

 

[martin j]

What kind of binocs are they?

if they are reputable brands, then check into warrenty, if not then it maybe is cheaper to buy a new pair then to have them repaired

 

[Thirteenth Star]

One pair is made by Barska. I purchased them a few years ago, on sale at Big 5 for $50 (regular price was $150). The other pair were a gift and simply say "Eddie Baur".

Neither have been left in a particularly warm environment.