My
4" refractor can outperform a 20 year old 10" reflector.



Uh, Donal....a Cave Astrola reflector from the early 80's will easily
top the highest end 4" refractor. It's simply going to collect too
much light over the 4 and transmission coatings don't equal raw
aperture. They've been making VERY good mirrors for even longer than
20 years.
I thought you knew something about this, but it sounds more like
you've read a lot of Vixen and Tak ads.


R.