If a manufacturer states that his binoculars are nitrogen filled and then goes on to state that all AIR to GLASS surfaces are multicoated, does that mean that only the front outer surface of the front objective and the exterior surface of the ocular lens, are the only surfaces multicoated? Since the interior lens surfaces are no longer subjected to AIR since being replaced with nitrogen? Also is there any advantage to nitrogen filled vs argon filled?
Air is actually a gas mixture that is mostly (78%) nitrogen. The thing with filling the binoculars with DRY nitrogen (not containing water vapor) is that it makes it internally fog free. Argon, or any other nonreactive gas works as good, not better.
That all air to glass surfaces are multicoated should mean Fully MultiCoated.
Hi Cappi,
There is a simple explanation of coatings here:
http://www.celestron.com/c3/support...barticleid=1626
This is just the first site that popped up on Google. Essentially you should be looking for both fully multicoated and phase coated in roof prism binoculars for best performance.
Obviously water getting inside binoculars will do damage of one sort or another. When pairs are waterproofed, the oxygen and water vapour are usually flushed out and may be slightly pressurised. This is to inhibit microbial growth. I know of no evidence that argon has a practical advantage over nitrogen.
David