Soon after completing the floor and walls of my new Observatory, it was time to take some astrophotos. Rising high early in the evening is the Andromeda Galaxy. Located in the Andromeda constellation, (midway between the Great Square of Pegasus and Cassiopeia constellations) The Great Adromeda Galaxy spans the width of more than 5 times the apparent diameter of the moon in the night sky. Andromeda is larger than our own Milky Way, and also our largest, closest neighbor.
This is an example of how image processing works. A recent spat about NASA photo-shopping their images drove me to type up some thoughts on how this actually works and why it has to be done. This is how Amatuers, Professionals, Astronomers and NASA scientists would do this. The tasks are the same, but the tools are different. I don't for example have a 30 foot curved mirror and a camera with a sensor the size of a cyndar block. What I am using is basically a large telephoto lens and specially-modified Canon DSLR camera. The first image is one single 'Sub Exposure' The second image is the result of stacking several hundred 'sub exposures' to create a single image with the combined signal and then 'balancing' the colors. There's too much red for example because of light pollution and because the red channel of the camera is more sensitive than the green and blue channels. Your camera fixes this automatically using something called 'white balance.' Yes, your camera 'Photoshops' the image for you so it doesn't look like crap! The is what a 'raw' image truly looks like before that happens! The last image represents the same image after it has been stretched and enhanced with Photoshop to bring out fainter details and make the image more pleasing to the eye. Nothing in the process is 'fake.' It's just a matter of collecting light and presenting it in a way the our eyes can grasp it.
Just a quick look at how my work is doing compared to a benchmark photo by a highly experienced amatuer astrophotographer. By comparison of equipment, what I'm using is dirt cheap and not at all specialized. For example, my camera was never intended to do astrophotography, but it can. While his camera is designed specifically for the task. The telescope i used is a flea market bargain compared to the telescope he used. I estimate the cost of the equipment he used to be in the neighborhood of about $45,000. I did mine for the cost of a PC, a DSLR camera, and a $350 "kid's" telescope a cheap mount and a small shed in the backyard to give it all a home. The comparison let's me see where some of the faults are in my technique and equipment. One of the things that I must improve is my mount. This would make the stars smaller and more round. A larger telescope would also help with getting better resolution. And finally a specialized filter to block light pollution. Even with this things, I can't hope to expect to get results like this. But i can get close! Someday I might.