The Crescent Nebula is an object worth coming back to year after year, and I’m much happier with this year’s version than any other. The improvement is due to better collimation of my AstroTech AT8RC, thanks to TS Optics TSRCKOLLI (review soon), as well as dedicating a lot of time to the OIII channel. I also switched reducers from the CCDT67 to the TS Optics 0.8x RC reducer. The CCDT67 couldn’t cover the full APS-C chip of the ASI2600.
I continue to be pleased with the ZWO ASI2600MM. What a fantastic camera. The low noise and lack of amp glow makes it a joy to use.
- Exposures (gain=100, -10ºC):
- H-alpha (5 nm): 54 x 300s = 4h 30 m
- OIII (5 nm): 145 x 300s = 12h 5m
- Total exposure time: 16 hours 35 minutes
- Taken Jun 4, 5, 6, 15, 2021 from Doylestown, PA
- Telescope: AstroTech AT8RC w/TS Optics 0.8x reducer (f/6.5), effective f.l.=1295 mm
- Camera: ZWO ASI2600MM-Pro with Astrodon filters
- Mount: Takahashi EM-200
- Guiding: ZWO ASI120MM on SW EvoGuide 50ED
- Processing: AstroPixelProcessor, PixInsight