Chris1011 wrote:

It doesn't "correct" false color any more than any other achro design. In
fact, it is nothing but a conventional achro design.

Except for a few very expensive glass types, the vast majority of glasses
produce essentially the same longitudinal chromatic error. The blue part of the
spectrum ends up at a point farther out from the green. The perceived error is
dependent on the focal ratio and any kind of filtering that may be used. Longer
focus lenses put more of the spectrum into reasonably sharp focus. There is
nothing in what I have said above that any optical designer would argue with.

A common misconception among amateurs is that lens design is some kind of
secret thing that requires uncommon knowledge to do. The fact is, almost anyone
can learn to do it well rather quickly. Once the fundamentals are learned, it
is no great feat to design any kind of lens, achromat, ED or zero color
apochromat. There are probably several dozen people that I know who can design
a world class zero color apo in less than 10 minutes using a fairly simple
design program. An achromat would take maybe 2 minutes.

Designing one is a piece of cake, the real chore lies ahead, when you want to
make one in the flesh. This takes a lot of knowledge that not too many people
world-wide have. There are plenty of optical shops that cannot make a working
lens to the level of accuracy required by most discriminating amateurs. They
can make lenses suitable for film imaging - no big deal, but better than
diffraction limited with proper control of chromatic aberration is usually
beyond most shops. If you can find a good shop to do excellent work (in China,
Russia, or elsewhere), count yourself extremely fortunate.

Roland Christen

Roland

Nobody was arguing the points you make, which are good ones. We've heard it all
before, though, "an achromat is an achromat is an achromat". You'd think by all
the bs (from others) that someone couldn't improve on the design of the rest of
the scope and make the achro the best that it can be... take the limitations to
the limit. Stellarvue has done this and on top of that they offer top notch
service. You always know that the scope you receive is going to be a good one, and
if for whatever reason it aint... return it. Simple stuff.

These type of threads are created by Stellarvue bashers who just can't get over
themselves.

Vic has made some mistakes in his promotional campaign for his company. Okie
dokie. They get corrected as things move along.

One thing that can't be said is that his scopes are crap. On top of that they are
getting better all the time as witnessed by the Dyer review of two Stellarvue
scopes in Sky and Telescope.

What these guys (the Stellarvue bashers) are on about is a mystery to me...
everything they discuss is ancient history. Vic has moved forward and addressed
these complaints..."because he listens to his customers".

Roland, to me it's akin to bashing you for not making your scopes better 10 years
ago because you make them even better today. I do admit that your promotional
campaign has been quite different. ;-)

You'd think the Conservatives would be on here telling people they are unpatriotic
for attacking a home grown buisness like Stellarvue. ;-)

- Don