ASTRO: Open Star Cluster M-41 in Canis Major

This image could be sub-titled "Astronomers discover giant arc in the sky."
Of course we all know that it's really just an artifact caused by Sirius
being just outside of the frame.

The image a crop from a 10-minute exposure with a Canon Rebel DSLR thru a
Brandon 80mm refractor.

For more info on M-41, see: http://www.kopernik.org/images/archive/m41.htm

George N

George Normandin wrote:

This image could be sub-titled "Astronomers discover giant arc in the sky."
Of course we all know that it's really just an artifact caused by Sirius
being just outside of the frame.

The image a crop from a 10-minute exposure with a Canon Rebel DSLR thru a
Brandon 80mm refractor.

For more info on M-41, see: http://www.kopernik.org/images/archive/m41.htm

George N

I always liked it visually but just too low for me to image here. Now
if you want to lend me that Brandon I'll see what I can do...

Doubt it is up to a full 35mm size frame however. But with my seeing
down there you'd never notice.

Camera does give nice color to the stars. Makes the combination good
for such clusters.

Rick

--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".

"Rick Johnson" wrote
........
The image a crop from a 10-minute exposure with a Canon Rebel DSLR thru a
Brandon 80mm refractor.

........
I always liked it visually but just too low for me to image here. Now if
you want to lend me that Brandon I'll see what I can do...

Doubt it is up to a full 35mm size frame however. But with my seeing down
there you'd never notice.

Camera does give nice color to the stars. Makes the combination good for
such clusters.


Rick,

I wish that we had gotten the 2-inch focuser version of that old 80's era
telescope. I'm sure that it would work well with a 35mm size chip using the
Astro-Physics field curvature corrector lens. However, that lens only fits a
2" focuser. We can't complain too much: Kopernik as two of these Brandons
that were donated by the owner of VERNONscope. In addition to doing duty as
"finders" now, they have been on a few solar eclipse expeditions and other
trips over the years. This era Brandon uses a Roland Christen made triplet
lens, but of course it was optimized for film not CCD, so in needs to have
the IR filtered out - not a problem with an un-mod'ed DSLR. For visual use
these scopes came with a 1.2x Barlow lens designed to screw into the scope
side of the diagonal.

George N

George Normandin wrote:
"Rick Johnson" wrote

........
The image a crop from a 10-minute exposure with a Canon Rebel DSLR thru a
Brandon 80mm refractor.


........
I always liked it visually but just too low for me to image here. Now if
you want to lend me that Brandon I'll see what I can do...

Doubt it is up to a full 35mm size frame however. But with my seeing down
there you'd never notice.

Camera does give nice color to the stars. Makes the combination good for
such clusters.



Rick,

I wish that we had gotten the 2-inch focuser version of that old 80's era
telescope. I'm sure that it would work well with a 35mm size chip using the
Astro-Physics field curvature corrector lens. However, that lens only fits a
2" focuser. We can't complain too much: Kopernik as two of these Brandons
that were donated by the owner of VERNONscope. In addition to doing duty as
"finders" now, they have been on a few solar eclipse expeditions and other
trips over the years. This era Brandon uses a Roland Christen made triplet
lens, but of course it was optimized for film not CCD, so in needs to have
the IR filtered out - not a problem with an un-mod'ed DSLR. For visual use
these scopes came with a 1.2x Barlow lens designed to screw into the scope
side of the diagonal.

George N

When I lived in Nebraska I had a neighbor who ran a machine shop. He
could make anything I needed to mate anything to anything. He retired
and died a year later. What a loss. His rates were really low and
quality high. I still use a lot of his stuff. I'm sure he could have
made something to mate today's 2" focusers to that tube. He did similar
jobs for me that worked perfectly. He'd say the threads weren't what he
wanted or it didn't turn quite right. I never felt what bothered him at
all. I miss the guy. Maybe there's someone in your area with similar
abilities.

Rick
--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".