Peter,
You're not confused. Aperture wins, as usual. As Rich points out,
perhaps the only advantage is the lack of diffraction spikes. But at
what price? There have been several articles in S&T about how to make
a low-cost curved spider, which also eliminates the spikes. And they
are now available commercially (using carbon fiber) as well. (Caveat:
the curved spider eliminates the spikes, but it does not eliminate the
contrast loss due to the spider; the diffraction is still there, just
not concentrated into lines.)
I'm with Rich and Leonard. I'd rather have the 6" Newt (with or
without the curved spider).
Bob J
--- rnapo <rnapo@No-Spam> wrote:
> No diffraction spikes.
>
> I would rather have the 6" Newt.
>
> Rich
>
> > I'm confused. I just read the S&T article on Orion's 3" off axis
> reflector.
> > I was actually interested in this, because it is clearly so
> unusual. From
> > the article though, when compared to Orion's *cheaper* 6"
> newtonian, it has:
> >
> > - less light grasp (obviously)
> > - the same size tube
> > - (surprisingly!) less contrast
> >
> > What am I missing here? Apart from it being gimicky, what
> advantages does it
> > offer the observer?
> >
> > Pete
> >
>
>
>
Received on Sun Mar 6 10:59:23 2005