The Swan Nebula - M17

CCD imaging details:

Camera SBIG ST-7XME with SBIG CFW-8 color filter wheel
Telescope Meade LX-200 10"
F-ratio f/3.3 (Meade f/3.3 focal reducer)
Exposure strategy
Took 60 red 10 second images, 60 green 10 second images, 60 blue 13 second images, and 60 luminance 10 second images using CCDSoft Version 5. 
AutoGuiding Not used
Autoguider exposure time ---
guide star ---
Date of Photo 9:57 to 11:35 PM, 19 September 2003
Location Our back yard, Tempe, AZ
Additional image processing Used CCDSoft "Align Folder of Images" to align all of the images and store the aligned images in a new "aligned" directory.  Then created one directory each for aligned red images, blue images, green images and luminance images and transferred red images to red directory, green images to green directory, etc.  In CCDSoft, did a "Combine folder of images" addition operation on each of the four directories.  This resulted in one red stacked frame, one green stacked frame, one blue stacked frame and one luminance stacked frame.  Read the four images into AIP4WIN and, on the luminance image, did a Van Cittert deconvolution with Gaussian blur of 1.2, Noise Reduction .5, 20 iterations, high-frequency only processing to produce a sharper luminance image.  Then did a Join Colors operation to create a color image.  Used "Manual Settings" and reduced Gamma to .5, increased Color Saturation to 2, and reduced luminance fraction to .5.  Saved image as a JPEG file.  Read file into Paint Shop Pro to run edge-preserving-smooth noise filter (value 2) followed by an unsharp-mask operation of  radius 3, Strength 50, Clipping 5 and saved the result.  Read result image into AstroPic, an image processing program I wrote, and ran two iterations of my color brightening algorithm (it brightens using an inverse exponential function so brighter things remain unchanged but dimmer things get brightened.)   Result image is what you see...
Posted  20 September 2003