It's been quite a while since I've posted here. I wonder if I can get
some opinions on a shot I took last night.

I just gotta new Canon EOS and some other things for my reflector. I
run my first set of shots last night. This was a 30 second exposure at
ISO 200 through a 25mm eyepiece on a 8" scope.

http://www.geocities.com/spiral_72/astronomy3.html

Other than the obvious tracking problem, whadya' think?

What's with the star at the top of the field? I saw that all night.

Are the colors from the nebula, or do I have some sort of defraction
problem?

I spent a lot of time on the focus without too much luck. Is the
blurryness a focus problem, or are pixels saturating?

Something I thought of after I come in: The camera has a diopter
adjustment on the viewfinder. I may need to set it, as it may be
distorting my "perceived" focus.

It's been quite a while since I've posted here. I wonder if I
can get
some opinions on a shot I took last night.

I just gotta new Canon EOS and some other things for my
reflector. I
run my first set of shots last night. This was a 30 second
exposure at
ISO 200 through a 25mm eyepiece on a 8" scope.

http://www.geocities.com/spiral_72/astronomy3.html

Other than the obvious tracking problem, whadya' think?

Are the colors from the nebula, or do I have some sort of
defraction
problem?
Then look like chromatic abberation combined with the

It's been quite a while since I've posted here. I wonder if I can get
some opinions on a shot I took last night.

I just gotta new Canon EOS and some other things for my reflector. I
run my first set of shots last night. This was a 30 second exposure at
ISO 200 through a 25mm eyepiece on a 8" scope.

http://www.geocities.com/spiral_72/astronomy3.html

Other than the obvious tracking problem, whadya' think?

1. What type of reflector? Newtonian?
2. What type/brand mount?
It's the older Orion Sky View F4 with the stock EQ mount. I am running

3. Did you carefully polar align the mount?
The polar alignment should have been pretty close, although it looks

4. What nebula were you trying to shoot?
Wow. That bad huh? It was supposed to have been the Orion nebula.

5. Why were you using an eyepiece? Nebulae can usually be
shot using prime focus projection. When they need to
be magnified as with planetary nebulae a barlow 2x or 3x
is usually enough.
It was prime focus projection with a 25mm Plossl. I did not use a

Are the colors from the nebula, or do I have some sort of
defraction
problem?

Then look like chromatic abberation combined with the
off axis coma suggested by Sam Wormley

--
Rick Evans
---------------------------------------------------------------
Lon -71° 04' 35.3"
Lat +42° 11' 06.7"
---------------------------------------------------------------
Webcam Astroimaginghttp://mysite.verizon.net/hiltonevans33050/astroimaging/astroimaging.htm

It's been quite a while since I've posted here. I wonder if I can get
some opinions on a shot I took last night.

I just gotta new Canon EOS and some other things for my reflector. I
run my first set of shots last night. This was a 30 second exposure at
ISO 200 through a 25mm eyepiece on a 8" scope.

http://www.geocities.com/spiral_72/astronomy3.html

Other than the obvious tracking problem, whadya' think?

It's the older Orion Sky View F4 with the stock EQ mount. I am
running
a single axis clock drive.

3. Did you carefully polar align the mount?
The polar alignment should have been pretty close,
To get a really good alignment you need to adjust

It was prime focus projection with a 25mm Plossl. I did not use
a
barlow this time, because it would magnify the tracking error.

If your were using an eyepiece then you were doing eyepiece
projection. Prime focus imaging using the main mirror only.

It's been quite a while since I've posted here. I wonder if I can get
some opinions on a shot I took last night.

I just gotta new Canon EOS and some other things for my reflector. I
run my first set of shots last night. This was a 30 second exposure at
ISO 200 through a 25mm eyepiece on a 8" scope.

http://www.geocities.com/spiral_72/astronomy3.html

Other than the obvious tracking problem, whadya' think?

What's with the star at the top of the field? I saw that all night.

Are the colors from the nebula, or do I have some sort of defraction
problem?

I spent a lot of time on the focus without too much luck. Is the
blurryness a focus problem, or are pixels saturating?

Something I thought of after I come in: The camera has a diopter
adjustment on the viewfinder. I may need to set it, as it may be
distorting my "perceived" focus.

On Feb 8, 10:19 am, "spiral_72" <spiral...@yahoo.com> wrote:





It's been quite a while since I've posted here. I wonder if I can get
some opinions on a shot I took last night.

I just gotta new Canon EOS and some other things for my reflector. I
run my first set of shots last night. This was a 30 second exposure at
ISO 200 through a 25mm eyepiece on a 8" scope.

http://www.geocities.com/spiral_72/astronomy3.html

Other than the obvious tracking problem, whadya' think?

What's with the star at the top of the field? I saw that all night.

Are the colors from the nebula, or do I have some sort of defraction
problem?

I spent a lot of time on the focus without too much luck. Is the
blurryness a focus problem, or are pixels saturating?

Something I thought of after I come in: The camera has a diopter
adjustment on the viewfinder. I may need to set it, as it may be
distorting my "perceived" focus.

You can make a focus plate, punch out 3 or 4 holes in a paint can lid
I use a 10 inch scope and a plastic 5 gallon lid. Point at a star and
if your scopes out of focus you will see as many stars as holes in
your plate, foucus till you have one image and your focus will be good
to go. PS I think Orion makes a plate if you want prefab.- Hide quoted text -

- Show quoted text -

A focus plate. Might it be called something else? A google search
turned up pretty much nothing. I did a web and an image search.

On 9 Feb 2007 06:15:28 -0800, "spiral_72" <spiral_72@yahoo.com> wrote:

A focus plate. Might it be called something else? A google search
turned up pretty much nothing. I did a web and an image search.

They are actually called Hartmann masks.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com