Re: [APML] Newton-cassegrains: opinions sought

["Stuart Heggie" <stuart.j.heggie@sympatico.ca>]

Rick - the Orion shot is beautiful! The M1 seems a bit thin on signal but
based on my own attempts, I'd be happy if my autoguider would stop moving so
my stars are round!

Stuart Heggie
http://www3.sympatico.ca/stuart.j.heggie/Stuart.J.Heggie/
Flesherton, Ontario, Canada

----- Original Message -----
From: "Rick Krejci" <apml@ricksastro.com>
To: "Discussion of Film Astrophotography" <astro-photo@seds.org>
Sent: Thursday, January 08, 2004 10:20 PM
Subject: Re: [APML] Newton-cassegrains: opinions sought


> I just acquired a CN212 and use it for digital photography.  Here is a
Canon
> 10D image using newtonian mode
>
> http://www.ricksastro.com/Gallery/htm/10D_M42.htm
>
> It is slightly cropped and still shows some elongation in the Corners.
I'm
> using the standard (if you can call anything standard in Tak land) Wide T
> ring, so I'm assuming the spacing from the corrector should be OK.  I may
> need to experiment some.
>
> Here is a SXV-H9 CCD image in cassegrain focus with their f9.9 reducer:
> http://www.ricksastro.com/Gallery/htm/SXV_m1_cn212cat.htm
>
> Thus far, after about a month of ownership, I like it quite a bit, but I
> might be concerned if I were using it for a full 35mm frame in newt mode.
> The optics are fantastic, and the focus shift is minimal.  Collimation is
> very solid when changing optics and it takes about a minute.  I've had an
> 8", 10" and 11" SCT, and I would choose the CN212 over any of them, mostly
> for it's flexibility and pinpoint optics.
>
> Rick Krejci
> http://www.ricksastro.com/
>
>
> ----- Original Message -----
> From: "Emmanuele Sordini" <vega@bloomingstars.com>
> To: <astro-photo@seds.org>
> Sent: Thursday, January 08, 2004 4:23 PM
> Subject: [APML] Newton-cassegrains: opinions sought
>
>
> > Hi all,
> > searching for a more advanced light bucket than a vanilla SCT, I thought
> > about going for a top-quality Newton-Cassegrain (~f/4 - f/15), such as
the
> > Tak CN-212 or others. That would make two instruments for the cost of a
> > single one. My fields of activity are:
> >
> > 1) deep-sky film photography (otherwise, I wouldn't be posting on APML
> > :-)), and
> > 2) high-resolution planetary imaging with webcams.
> >
> > Anybody have experience with such instruments, especially as compared to
> > equally-sized SCTs? I feel that they might be better overall, but with
> some
> > drawbacks (less compact, more sensitive to local turbulence, and a
hassle
> > to collimate, especially when switching configuration). Furthermore,
they
> > don't seem to be very popular among amateur astronomers.
> >
> > Any opinion/advice will be highly valued.
> >
> > Thanks in advance and clear skies,
> > Emmanuele Sordini
> >
> > _______________________________________________
> > Astro-Photo mailing list
> > Astro-Photo@seds.org
> > http://seds.org/mailman/listinfo/astro-photo
> >
> >
>
>
> _______________________________________________
> Astro-Photo mailing list
> Astro-Photo@seds.org
> http://seds.org/mailman/listinfo/astro-photo

_______________________________________________
Astro-Photo mailing list
Astro-Photo@seds.org
http://seds.org/mailman/listinfo/astro-photo