CREATING ASTRO-PHOTOS WITH THE HELP OF OTHER

Improving Astro-Photos with the help of others

An internet Story

My interest in astronomy started out innocently enough with the purchase of my first telescope a 4” refractor. But my hobby

expanded quite rapidly when I decided to move up to a Takahashi FS-128 APO refractor and a Mountain Instruments MI-250

mount and then my interest evolved to astrophotography. I started out slowly but with the help from other astrophotographers

and a lot of research on the Internet I started making advances in my image taking and processing skills. The following steps describe

the processing techniques I performed on the Orion Nebula (M42) image taken from my back yard March 03, 2003.

Using Picture Window Pro 3.1, I stacked the two images using the Composite function with the operation set to “Add” and the

alignment set to “multi-point”. I usually obtain a better alignment using the multiple points setting.

Jerry Lodriguss is one of several astrophotographers that have taken the time to write his techniques for processing images. Jerry

has recently released his long awaited Image processing CD called “Photoshop for Astrophotographers” and you can find a link

to it on his web page @ http://www.astropix.com

Jerry has a description of a stacking technique on his web page called “Aligning Images in Picture Window”

@ http://www.astropix.com/HTML/J_DIGIT/PWALIGN.HTM which I referenced to stack the following images.

30 minute exposure 45 minute exposure Resulting image

After stacking the above images I then performed a blurring function using a software program provided by Pleiades

Astrophoto @ http://www.pleiades-astrophoto.com/en.html called “Selective Gaussian Blur Noise Reduction” (SGBNR)

shown on the right image “Image after SGBNR”. I used the auto key to set the RGB Mask Histograms and left the

rest of the setting set to there default.

I have read recommendation to perform the SGBNR function after all the processing has been completed, but on

this image I felt smoothing the image prior to copying the core to the overexposed image would give me a smoother

overall image. I have found that most of the techniques used for astrophotography have a great deal of latitude and

each image will require some judgment as to the techniques used and the amount of processing that is required to

process an image to a quality level you will be happy with.

Now I am ready to correct the over exposed core area in the image by combining the two stacked long exposures

with a short exposure image using a technique written by Jerry Lodriguss called “Combining Two Different Exposures”

Image after SGBNR 7 minute exposure Composite image

]

You can see from the image above “Composite image” I successfully replaced the burned out nebula core area with a more

detailed and pleasing portion of the 7-minute exposure core area. After replacing the core area I rotated and cropped the image in

PhotoShop to delete the area that was outside the second image during the two long exposure-stacking phase.

The composite image still needs a little help with its contrast and detail so I performed another technique by Jerry Lodriguss

called “Real Digital Unsharp Masking” @ http://www.astropix.com/HTML/J_DIGIT/USM.HTM this increased the contrast and detail

of the image.

As a final step I enhanced the image by performing the following functions in PhotoShop 6.0: Levels and Color Balance.

Final Processed Image

There are a host of articles that I have used to advance my astrophotography imaging and processing skills including articles on

how to use my equipment and there is even places to go for information on CCD and film questions. By using the Internet and

making friends with common astrophotography interests the learning curve can be greatly reduced. No matter what your level

of expertise anyone can benefit from the vast knowledge that is available on the Internet.