On 4 Sep, 01:07, "Capt. Rob" wrote:
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.


Wrong!! I've taken some photographs!
My coments are based on personal experience.
Your comments are based on personal ignorance.

Before you argue this point, perhaps you will tell us
more about your photo of M31. You pretended that
you took it from your back yard. I live about the same
distance from London as you do from NY. Do you
want me to show the same thing from here?


Regards


Donal
---

On Sep 4, 6:30 pm, wrote:
On 4 Sep, 01:07, "Capt. Rob" wrote:

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.

Wrong!! I've taken some photographs!
My coments are based on personal experience.
Your comments are based on personal ignorance.


Donal, you must be crazy. I've looked through a William Optics Triplet
110mm APO vs. an old Cave Astrola 8. The bigger mirrors easily out-
resolved the APO of course. It's not like they couldn't make great
mirrors in the 70's and 80's, you numb-nut! Transmission coatings have
improved things a bit and love small beautiful refractors, but don't
be crazy. When it comes to scopes, SIZE MATTERS.


Before you argue this point, perhaps you will tell us
more about your photo of M31. You pretended that
you took it from your back yard. I live about the same
distance from London as you do from NY. Do you
want me to show the same thing from here?


Donal, why not just throw an egg into the air and let it land on your
face? I'm in Kent Cliffs, quite high up. I get very little sky glow
here and on a good fall night I can get a pretty dark sky. The shot
was taken from my front deck using the CPC-800 with NO WEDGE, which
meant I had to keep the exposure down to about a minute with a 90mm
lens on a D300, which in turn was piggybacked on the scope. Without a
wedge you get field rotation if you use longer exposures. I have a
wedge, but it's still packed up in the original box. Settings on the
D300 were ISO 1000 at F/4.5.




R