Thread: Are Refractors Nitrogen Purged?
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Old 25-08-2014, 08:16 PM
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dannat (Daniel)
daniel

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Join Date: Sep 2007
Location: Macedon shire, Australia
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no only spotting scopes & WP binoculars -most refractors are open at the ep end -except for the petzval types with rear elemnents
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