Overview:

Setting up the telescope for a night of imaging is only half of the equation. Capturing the images and post-processing them can be time consuming but the end result can also be quite rewarding. Depending on the equipment and software used there are many methods to capture and process the image data.  The following steps are simply the way I capture and process my images using a Meade LX90 and DSI Pro II imaging camera.

The following is an example of my equipment setup when preparing for a night of  imaging:

Once the telescope has been powered on and aligned it can then locate objects in the sky. The Autostar controller contains a database of over 12,000 astronomical objects. An object is selected, and the go-to button is pressed. The telescope will now locate that object and center it in the field of view then track the object. Once this is performed the object can then be imaged.

There are a number of  various programs that can be used to capture images.
          • For Lunar, Solar, and Planetary imaging I prefer to use the Meade Autostar Envisage and K3CCDTOOLS programs.
          • For Deep Space imaging with the Meade DSI Pro II I use the Meade Autostar Envisage and Stark Labs Nebulosity  programs.

Here's an example of the Meade Envisage program:
 

(Click on the image to enlarge)

Using Envisage to capture images can be somewhat complex but the more it is used, the more familiar the user will become with the program. Images can be captured in a number of file formats but I have found that the best format to capture with is FITS. More on this later.

My Save options are to 'Save All Uncombined Images'. Once the image has been located, centered, focused, and adjusted, clicking the Start button will begin the process of capturing images. By selecting the 'Save All Uncombined Images' option, each image will be captured separately and a combined image will be produced as well. Separate images can then later be combined using various programs like Registax,  Astrostack,  Meade Autostar Suite's Envisage,  or  DeepSkyStacker  (which is my personal choice). 

Here's an example of the Stark Labs Nebulosity program:

(Click on the image to enlarge)

Nebulosity is designed to be a powerful, but simple to use capture and processing application for a wide range of astronomy CCD cameras. Many cameras are supported for capture and images from just about anything can be processed (support for many FITS formats, PNG, TIFF, JPEG, CR2/CRW, etc). Its goal is to suit people ranging from the novice imager who wants to create his or her first images to the advanced imager who wants a convenient, flexible capture application for use in the field.  In it, you get a host of purpose-built, powerful tools to make the most out of your images (e.g., Digital Development Processing, traditional alignment/stacking (equatorial and alt-az), Drizzle alignment/stacking, Bad Pixel Mapping, LRGB tools, real-time tricolor histograms for color balancing, star tightening via edge detection, adaptive scaling of stacks, Canon CR2/CRW RAW Bayer matrix loading, 32/96-bit accuracy, etc.)

If I am creating a color image, I capture 4 sets of individual images. They are Luminance, Red, Green, and Blue using the provided filters that come with the camera.  See the following image which shows the camera, filter bar,  and focal reducer:

(Click on the image to enlarge)

My  image processing program of choice is DeepSkyStacker. This freeware program is an improvement over the Meade Image Processing program and provides additional features which makes my image processing quicker and with better results. DeepSkyStacker can be downloaded from  http://deepskystacker.free.fr/english/index.html.

The screenshot above shows a number of raw images that have been added to the DeepSkyStacker program.  The individual images are of M1, The Crab Nebula. In the example above, this group of Luminance (mono) images will be stacked together in DeepSkyStacker to create one composite image. The procedure will then be repeated for my individual Red, Green and Blue images. Once completed, I will have four composite images that will then be aligned with each other in Autostar Image Processing then post-processed in Photoshop to create the final image. Note how faint the Crab Nebula looks. That is because the image above is only one single raw image. Stacking many frames on top of each other, will bring out more detail. Combining all four sets of stacked images together in Photoshop and post-processing will bring out even more detail.

With Meade Autostar IP astronomical image processing software one can perform many of the same image processing tasks that a professional astronomer would do on a large institutional computer. With Meade Autostar IP you can:

                • Enhance high resolution images using advanced image processing techniques.

                • Determine stellar magnitudes directly from electronic images, and a number of other powerful features.

One can also use Meade's Autostar Image Processing program to stack the 4 combined images. Image Processing will align all four combined images with each other and create four aligned images so that each combined image will line up with the next. The way to do this is:

Example of 4 separate combined images before aligning.

(Click on each image to enlarge)

Once the 4 unaligned images have processed with each other Image Processing will automatically create four aligned images into the same directory as the four unaligned images. If the first alignment is not successful, or additional aligning is needed, process the four aligned images and create a new set of four images using the same process as above.  Once the images are aligned, the result will look something like the following example:

The four aligned images are now ready to be post-processed in Photoshop.

FITS Liberator:
Like all of the above steps, there are a number of different tools available to process one's images. With post-processing, Photoshop is used by many because of the quality of the software, and the ability to bring out the rich detail of an image. The following will not be attempt to guide one through each and every step within Photoshop. Rather the following steps will serve as a guide for processing an image. More detailed links to step-by-step processing will be included below.

What are FITS images?
FITS stands for `Flexible Image Transport System' and is the standard astronomical data format endorsed by both NASA and the IAU (International Astronomical Union).  FITS is a file format used for many years in astronomy to store and move images from telescope-based instruments. It has been designed to provide capabilities needed by astronomers but is not a generally known format such as JPEG or TIFF.

In order to process FITS images, either download  a free FITS Liberator plug-for Photoshop (v2.2), from  spacetelescope.org, or download a standalone version (v3) that does not require Photoshop from  The European Homepage For The NASA/ESA Hubble Space Telescope.  Since I post-process in Photoshop I prefer the v2.2 plug-in.  The system requirements are as follows:

Once downloaded and installed, the FITS Liberator plug-in will open automatically in Photoshop after a FITS file is selected and opened. The FITS Liberator screen will look something like this:

It is at this point that the FITS image will be initially adjusted before it is further processed using the Photoshop tools. I use the White Level and Black Lever sliders in the Histogram to make my initial adjustment before selecting OK. Picker Tools (eyedropper icons to the left of the image) can also be used to automatically adjust the White and Black levels. Once adjusted, the image looks like this:

While the black level has now been adjusted, the object data is not as apparent. Don't worry. It is still there, and further processing in Photoshop will bring it out.

As I mentioned earlier, I use the Meade DSI Pro II imager. If I am capturing a mono image (Luminance) this is the only image I have to process. However when processing a color image, I will be manipulating 4 separate images - Luminance, Red, Green, and Blue (LRGB).

There are a number of methods used for post-processing the image in Photoshop. I recommend that the new user join the Yahoo DSI group. Once you become a member, you will find many helpful hints in the 'Files' section of this group that will walk you through the post-processing steps. I am also including the following  Adobe PDF documents that will walk you through the steps necessary to process and post-process your images. These documents are:
 

Photoshop Actions:
Photoshop is a very powerful graphics tool that can take hours and hours to master. As I began post-processing in Photoshop, I followed the guidelines in the documents mentioned above and had good success though time consuming.  I then became aware of a couple of software products called Astronomy Tools v1.6 by Noel Carboni and Annie's Astro Actions v3.3 by Anna Morris.  Both contain a set of Actions - or Macro Operation Sequences - that you load into Photoshop, producing top-quality results. These Actions were designed by Noel and Anna specifically for Astro-Imaging. Instead of manually processing individual steps in Photoshop, these actions can do this automatically for you. Some Actions encompass literally dozens of individual steps. This saves a lot of time in the post-processing experience. Both programs will install directly into Photoshop and each Action will be listed in the Actions tab. See the following example:

Astronomy Tools Listing

(Click on image to enlarge)

Annie's Astro Actions Listing

(Click on image to enlarge)

I now use both of these action programs on every image that I post-process as well as a certain amount of manual processing. While these actions are not a replacement for manual processing, it saves a considerable amount of  time. Both action programs are very affordable and the diversity between both programs complements each other well.

Before and After Images:

As I mentioned at the beginning of this section, I am not going to go through the post-processing of an image step-by-step. Using the guide documents I have provided, and a bit of time spent experimenting, one will quickly grasp the process of creating a final image. But for those interested, the following images of M101 - The Pinwheel Galaxy  will show what unprocessed images look like followed by the final image.

After combining the Luminance, Red, Green, and Blue images in Photoshop, and adjusting the combined image. this is the end result:

The following flowchart summarizes the steps taken from once the telescope has been setup until the final image is processed in Photoshop:

I recently read an article from a gentleman who stated that one can do CCD imaging as well in the city as in rural conditions. I don't know what equipment he is using, but I have found that dark site conditions produce the best images with the Meade DSI. His belief might be closer for objects such as M42, or star clusters, but when it comes down to those fuzzies, get out of the city and into a dark rural area whenever possible.

The following is a pretty accurate representation of the varying levels of light pollution. The images below this comparison are an example of the differences in quality between my suburban backyard and our clubs dark sky site. It is apparent that getting to a dark environment will greatly improve the quality of your images.

The M81 images below reflect the difference in image quality between my backyard, in the Suburban/Urban Transition, compared to Rural/Dark Sky Site. Each image was captured using the same equipment and exposure times.