A final processing of M81 and M82. This includes over 20 hours of RGBHa data, taken on different nights in March and April with the Esprit 120mm and the ASI183MM. I found 300 second subs at gain 111 would burn out most stars, leaving no color information anymore. Therefore I used the 300s subs as luminance channel, but in APP using only 50% of it’s luminosity (RGB Tool). On additional nights I captured 120s subs RGB with Gain 111. That’s still a high gain for the ASI183MM, resulting in burned stars, loosing there color, but somehow managed to get that processed in the right direction. The H-Alfa channel was obtained by 600 second-subs at gain 200 (35).
After cleaning & collimation, I tested the C11 with the Starizona F 7.2 reducer, the ASI183mm (way oversampled obviously), and guiding using a simple external 8×50 guider and the ASI290MC. Just as a test not bad. I’m not convinced the mirror shift did not have influence in this image. Focusing was a pain, needed to be done manually.
In total 13 hours and 20 minutes of RGBHa frames, both 120s and 180s went into this picture. You can just about see the external halo surrounding the galaxy itself, and details in as well the core as in the spiral arms. Esprit120, ASI183mm, Baader HaRGB.