As the title describes, I've made a 3 video series that shows how after I have created my sketches, how I take an image of them, transfer them to my computer and then refine and process them in GIMP. I show how I round and brighten my stars, how I sometimes enhance an image to make it match more of what I saw at the eyepiece and how I prepare them for publication. I hope this helps and if you have ideas on how to improve, I'd love to hear them in the comments either here or over at Paetron. The videos are housed on Paetron at EadsyAstronomy. You can join for free and receive email updates when I post there. If you're able and want to donate to support me sharing such content, please feel free to do so there. Again though, all the content is free. The Tutorial is at this LINK over on EadsyAstronomy.
Here is NGC 5557 a elliptical galaxy in Bootes that I sketched on July 23, 2025 at Cedar Mountain Wildnerness. The first is the raw sketch and the second is after I processed it in GIMP. I explain and show the differences and the reasons for the adjustments in my video.
Here are my observing notes: At 317x in the 7mm XWA 100 degree FOV eyepiece in my 17.5" f/4.4 dob, the galaxy shows as a round object with a very bright inner core and a stellar nucleus. The outer halo is very faint on the edge.
I made adjustments in GIMP to this sketch as I was happy with the actual galaxy I had sketched and I used GIMP to enhance the image so it matched what I saw in the eyepiece. More on the video!