My first 5 minute frame of M27 with my ZWO ASI 2600mc was sharp and looked a lot like my prior attempts at imaging M27 except the SNR was better than I expected. Although the classic Dumbell shape was obvious, I also noted some faint nebulosity beyond the outline of what I expected to see.  On closer inspection, the central star looked blue. I decided to try and image the faint nebulosity in narrow band H-alpha and O-iii. That decision led to many hours of imaging this summer on the few clear nights in my area. After my first night of imaging M27, I read a little more and realized that the central star is a very hot blue-white star of magnitude 13.5 (https://www.messier-objects.com/messier-27-dumbbell-nebula/). As I slowly acquired more and more images, the outer nebulosity was clearly strongly related to the O-iii and H-alpha signals in the central portion of the nebula. The cross-shape of bright H-alpha in the core aligns well with radiating H-alpha in the much fainter outer nebula.

My technical skills in presenting this information have been challenged due to the incredible dynamic range of image intensities - perhaps others may have suggestions how to improve upon my first attempts. After playing with these images several times, I made four goals: 1) to maintain small stars, 2) to keep the bluish color of the central star, 3) to avoid distorting or blowing-out the classic Dumbell shape in the central portion of the nebula, and 4) to display as much of the faint outer nebula as I could.

Using Pixinsight, I captured star colors and size with 1 hour of one-shot color RGB data and adjusted the display to optimize the central blue star. The core of the nebula was muted on these images. I used StarNet in Pixinsight to separate the stars and the nebula and kept the stars for the top layer of my project in Photoshop. I used 7.83 hours of H-alpha and about 2.25 hours of O-iii to make a synthetic (H)(Oiii)(0.3xH+Oiii) image. Many people make a synthetic HOO image which looks quite reasonable but the B channel also covers H-beta, which tends to co-localize with H-alpha. Adding a percentage of the H-alpha to the blue channel produces a more magenta tone rather than a stark red tone if the H-alpha is strictly in the red channel. I used StarNet to eliminate the stars from the synthetic HOO image. Even with all that effort, I could not compress the dynamic range adequately to show both the central and faint outer nebulosity. I chose to use Photoshop to display two ranges of the HOO data in different layers but may draw criticism for that approach. The combined three layers is my current image.

Before leaving this concept, I highly recommend looking at really deep images of M27 on Astrobin and on NASA posts (https://science.nasa.gov/m27-dumbbell-nebula and https://www.jpl.nasa.gov/images/weighing-in-on-the-dumbbell-nebula). I believe the information content of my image is high and robust. I'm suspect a more experienced post-processor could do better job displaying the data.