The Bode’s Galaxy (M81) and the Cigar Galaxy (M82) are located in the Ursa Major constellation, which is right outside my backyard. Taking advantage of clear night on 2/14, I decided to see if I could capture these two galaxies. I got everything set up, ready, and started imaging. Two and a half hours later, I started to process the images and boy was I disappointed. M81 and M82 were severely out of focus. I told myself no big deal and I could just wait for another clear night and image them again. Here is the output from the night of 2/14:
Three days later , on 2/17, I tried it again. Thinking I had a much better focus, I imaged the two galaxies for another 2.5 hours. As I was processing the images from that session, the same thing happened! I was out of focus again. How could this happen two times in a row? Taking a step back and do some research on focusing. Turns out, there was still a great deal to learn. The clouds rolled in after that night so this gave me some time to do some research into how to achieve a better focus.
Turning to youtube, I came across this fantastic tutorial by John Blackwell on understanding a Star’s Full Width Half Maximum (FWHM). Huh? What is FWHM? Turns out this four letter F word (not the one you are thinking about) is very important for determining whether your image in focus or out of focus...Read More >