Re: ATM Enhanced Coatings.

[epabcc@epa.ericsson.se (Bratislav Curcic)]

Chris Westland wrote :

> I suspect that it doesn't make that much difference visually.  But another
> advantage is that the additional layers of SiO make the coating more
> weather resistant, and physically tougher.

Enhanced Coatings are NOT "additional SiO". They can be 
a) MgF2 overcoated Al or silver, sometimes with multiple coatings (multicoatings)
   this combination can be up to 98% reflective
c) true dielectric coatings (up to 99.9% AT CERTAIN WAVELENTGTHS)

It _does_ make difference. Whether additional 10% or 20% is significant, it 
depends on you ...
I feel that enhanced coatings definetely make sense on secondaries (not so 
expensive, but equally effective). That is probably the most effective way to
spend few extra bucks ...

Bratislav