Astrophotography: Building Confidence

I have just posted my first through-a-telescope deep-sky astrophotos to
my web site. Excerpts from my caption:

"These two regions‹The Orion Nebula (M42) and the Pleiades Open Star
Cluster (M45) are so often photographed by amateurs that it is hard to
add anything new to them. What makes these two images special‹to me‹is
that they are my very first such images through an astronomical
telescope..."

" These images also represent first light for my new TeleVue 76
Apochromatic Refractor..."

"...These images are confidence builders for me; I have had doubts
about the feasability of making good astrophotographs under Maryland
skies, particularly because my home is half-way between Baltimore and
Washington, D.C..."

Don't expect these images to blow your socks off, though I will say
that I believe that my shoelace became untied while I was processing
M42.

http://www.davidillig.com/ast-m42m45050127.shtml

Davoud

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Davoud wrote:
I have just posted my first through-a-telescope deep-sky "These two
regions=8BThe Orion Nebula (M42) and the Pleiades Open Star
Cluster (M45) are so often photographed by amateurs that it is hard
to
add anything new to them. What makes these two images special=8Bto
me=8Bis
that they are my very first such images through an astronomical
telescope..."



Bravo! I wish my first deep sky photos (circa 1966) had looked this
good!

Peace,
Rod

WOW! These are just terrific, Davoud, especially for first attempts. Can
you tell me how precisely you were able to remove the sky glow from the
shots? I use photoshop, too, but haven't found the trick to getting
decent dark backgrounds. Whenever I leave my shutter open I record
increasingly gray background sky after a minute or so, as my conditions
are suburban. Any advice on how to get rid of it?

Nicely done, again. Congrats-
Chris


Davoud wrote:
I have just posted my first through-a-telescope deep-sky astrophotos to
my web site. Excerpts from my caption:

"These two regions‹The Orion Nebula (M42) and the Pleiades Open Star
Cluster (M45) are so often photographed by amateurs that it is hard to
add anything new to them. What makes these two images special‹to me‹is
that they are my very first such images through an astronomical
telescope..."

" These images also represent first light for my new TeleVue 76
Apochromatic Refractor..."

"...These images are confidence builders for me; I have had doubts
about the feasability of making good astrophotographs under Maryland
skies, particularly because my home is half-way between Baltimore and
Washington, D.C..."

Don't expect these images to blow your socks off, though I will say
that I believe that my shoelace became untied while I was processing
M42.

http://www.davidillig.com/ast-m42m45050127.shtml

Davoud

David,

Congrats those are very nice. I wish I could get that good with my 20d.
How did you get such good focus? Also was this via eyepiece projection
if so what magnification were you using?

What filter did you use? Did you do one exposure for the bright stuff?

I'd love to know your post processing steps.

Craig

In article , says...
I have just posted my first through-a-telescope deep-sky astrophotos to
my web site. Excerpts from my caption:

"These two regions?The Orion Nebula (M42) and the Pleiades Open Star
Cluster (M45) are so often photographed by amateurs that it is hard to
add anything new to them. What makes these two images special?to me?is
that they are my very first such images through an astronomical
telescope..."

" These images also represent first light for my new TeleVue 76
Apochromatic Refractor..."

"...These images are confidence builders for me; I have had doubts
about the feasability of making good astrophotographs under Maryland
skies, particularly because my home is half-way between Baltimore and
Washington, D.C..."

Don't expect these images to blow your socks off, though I will say
that I believe that my shoelace became untied while I was processing
M42.

http://www.davidillig.com/ast-m42m45050127.shtml

Davoud

Hi,

WOW! These are just terrific, Davoud, especially for first attempts. Can
you tell me how precisely you were able to remove the sky glow from the
shots? I use photoshop, too, but haven't found the trick to getting
decent dark backgrounds. Whenever I leave my shutter open I record
increasingly gray background sky after a minute or so, as my conditions
are suburban. Any advice on how to get rid of it?


Hmm, I am not Davoud, but, well, since he did not answer yet...
If you have access to a Unix/Linux box, you may be interested in the
darksky shellscript I have written:
http://www.bnhof.de/~ho4463/astro-scripts.html
It is not really a work of art, but it works for me (and I would be
pleased to hear your opinion if you try it out).
I am currently learning Tcl/Tk, so there will probably be a
cross-platform version of this (also with a GUI) in the future.
Greetings & Best regards,

Jan


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Craig M. Bobchin:
Congrats those are very nice. I wish I could get that good with my 20d.
How did you get such good focus? Also was this via eyepiece projection
if so what magnification were you using?

What filter did you use? Did you do one exposure for the bright stuff?

I'd love to know your post processing steps.

Hello, Craig,

Thanks for visiting my miserable little web site and for taking time to
post your kind remarks.

You can get "that good" with your 20D. As I noted on the web page
http://www.davidillig.com/ast-m42m45050127.shtml, I am a beginner at
deep-sky astrophotography. I didn't mention that I have considerable
experience with Photoshop.

Both M42 and M45 put a good mix of bright and dim stars in my camera
viewfinder, which I find convenient for focusing. I used a Canon Angle
Finder C at 2.5x magnification and focused for sharpness and contrast.
Using averted vision helped me focus.

Then I checked focus at the computer. A lot of folks like DSLR Focus
http://www.dslrfocus.com/, but 20D support is still in beta, and I
haven't been able to make it work. I used Canon's "Digital Photo
Professional" software to download the images as soon as they were made
in order to check focus. That means making a couple of short
(underexposed) images to start with to check focus. I did this on a Mac
PowerBook, but I'm sure it would work on my Windows laptop. The last
short exposure -- the one with good focus -- may be saved and the
region around the Trapezium used to paste into the final image to
compensate for overexposure in the stacked image. After I capture all
of my images on the PowerBook at the 'scope I move them via my 802.11g
wireless network to a more powerful Mac for processing. Keeps the
pixels from freezing out there in the cold observatory...

Other details are on the web page: camera at prime focus, and I used a
2" Lumicon Deep Sky filter. Eyepiece projection is incompatible with
wide-field photography.

I stacked the M42 image using Keith's Image Stacker on a Mac; Registax
under Windows would also work. For some reason, Keith's didn't do as
good a job for M45, so I used another Mac image stacker, Lynkeos, for
that target.

Then I went to work in Photoshop. I manage color, contrast and noise
exclusively with the curves control. It's important to note that my aim
is to produce pretty pictures that will look good on the web and in
print; I'm not a researcher and I'm not aiming to make research-grade
images. I work with Curves on the red, green, and blue channels
individually until I get an image that pleases me. I don't know a magic
formula for doing this, but in general, I reduce the blue at the dark
end, reduce the green across the spectrum, and increase the red as much
as I can, especially toward the bright end, while trying not to make
the dark background too red. The aim is to get a very dark background
in black, very dark gray, or very dark blue. Sometimes I work on a
selection, but one has to feather the edges a great deal -- 20 pixels
or more, sometimes -- to prevent the processed selection from standing
out like a patch on a quilt. At the very end I crop and resize as
necessary and use unsharp masking very carefully. Sometimes I do a
_real_ unsharp mask, i.e., I apply a blurred copy of the image to
itself. I'm going to try to further qualify the steps that I use, and
if I am able to do that I will include the information on a future
image and post a notice here.

I will make one more try at both M42 and M45 soon, and if there are
improved results I will post here.

Thanks again,

Davoud

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