Question about Canon (12x36) IS II Binocular

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Pattern appeared on interior of lens/prism

My Canao 12X36IS binos were stored for a season (indoors. When using them for the first time, I noticed a pattern like etching or dried condensation on when looking through them. It seems to be on the prism or lens interior surface. Any sugestions on how to fix. Is this just a cleaning issue?

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Re: Pattern appeared on interior of lens/prism

What you see is fungus . It comes off very easily BUT if allowed to grow it will damage coating and glass because the organism releases hydrofluoric acid. So the key is to clean as soon as possible. You can do this your self but be careful around the prisms because even slight movement here will upset your collimation ( will get 'double image')and then you will need to have your nbinocs aligned properly.

Posted on Sep 15, 2007

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I was given a pair of 10X42 powerview FOV293FT the Prisms seem to have shifted can they be repaired and would this be cost efective Ian South Africa

If there has not been a major blow, it is in most cases straightforward to align that double image.
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For adjustment of the double image binos come with three more common options. There are in some cases concentric adjustment rings around the front lenses. More frequently on porro binos there are adjustment screws on the prism housing. You find them under the front and rear edges of the rubber fascia. Or with roof prism binos you often adjust the angle of the eyepieces with in that case adjustment screws on their periphery
To adjust you first pull the two tubes apart a little, look then at something with horizontal and vertical lines in the distance, for example a building. The image will look like bino views in a movie film, with two different circular fields of views kissing each other in the middle.
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