The Session-Story of the Horsehead Nebula
Permanently clouds, and then? Clear sky at full moon! I did not want to ignore the possibility to get a new picture and went for the Horsehead Nebula.
Pleiades
At the early evenings, i did some exposures of the Pleiades for about 2 hours until the Horsehead Nebula rised over the house of my neighbour.
Horsehead Nebula
After Pleiades, i took photos of the Horsehead Nebula on both days for about 2 to 2,5 hours on each of them:

On both days, dew and frost came while i was exposing the nebula. It all went really well, beside the fact, dass dew and frost on the guide scope ended my exposure time a bit after midnight on the first day. After that, i ordred a heatband for the guidescope for the next sessions.
Same data – advanced processing
Lessons Learned
The most important thing i have learned is, that it is absolutely senseless to shoot Pleiades or any other “RBG” target at full moon. The material is truely only usefull to get thrown away. I think Pleiades will be my next target.
One thing that worked pretty well was the switch between the two filters. Before i switched to the L-Extreme, I refocused with the UV/IR Cut. Due to the fact that both filters are homofocal, the focus worked pretty well.
The post processing was all done in Affinity Photo. I really like the result. It is a little bit pity, that the small hole of clouds on the 3rd day was really tiny. I would have loved to add some RGB stars to the picture. Since i worked again on the flattener config after christmas, there will be no rgb on that picture and I declared it as finished. Then next year again …
Technical overview – Horsehead Nebula
Telescope | VIXEN ED80sf |
Focal Length | 600mm |
Aperture ratio | 7.5 |
Erecting Lense | TSFlat2 |
Filter | Optolong L-Extreme |
Mount | Skywatcher HEQ-5 |
Goto-Control | EKOS |
Mount Control | INDI |
Guiding Scope Focal Length | 162 mm |
Guiding Camera Chip | 4.8mm x 3.6mm, 8bit |
Guiding Camera Resolution | 1280×960 |
Guiding Software | EKOS, INDI |
Dithering | 3 pixel |
Camera | CANON EOS M100(a) |
Method | focal projection |
Camera Control | EKOS, INDI, Gphoto2 |
Photography Date | 12/20/2021 12/21/2021 |
Exposure-Time Lights | 48x180s |
Sensitivity | ISO 1600 |
Calibrationframes | Flats, Bias |
Processing Date | 12/23/2021 |
Reprocessing Date | 12/21/2023 |
Stacking, Integration | Affinity Photo |
Post Processing Software | Affinity Photo |
Image Editing | Affinity Photo |
Reprocessing Software | PixInsight |
Capture Place | Koblenz, Germany |
Lightpollution | Bortle 5 |
Scattered light | strong |