June and July consistently delivered terrible weather for astronomy—here in the northwest US. There was one clear-ish night somewhere in the middle of the waves of thunderstorms, torrential rain, and general cloudiness, but on that one night we were close to a full moon and a few hours of clear skies amid the weeks of cloud that followed that night wasn’t worth the effort. So I waited for the next opportunity. Last night, August 11th, I set up the Sky-Watcher mount (EQ6-R Pro) with the William Optics SpaceCat and my new camera, which I bought in June.
Here's the result of my first imaging run with the ZWO ASI2600MM Pro mono camera, cooled to -10C, Antlia 3nm Hydrogen-alpha Pro Imaging filter (2 inch). 52 x 300-second sub-exposures with minimal calibration (bias & dark, no flat frames). The ASI2600 is built around the monochrome version of the Sony IMX571 APS-C sized sensor, and although you can get away with 36mm unmounted filters, I went all the way to 2 inch mounted narrowband filters. And not even a hint of vignetting. I didn't use flat frames when stacking. So, am I impressed with the ZWO ASI2600MM Pro? Oh yeah.
I started narrowband imaging about ten years ago with Atik mono CCD cameras, moved through a couple QHYs, and settled on the ZWO ASI1600MM Pro—the smaller, older generation of this ASI2600. I've been using the 1600 for four or five years, and it was time to upgrade. The 2600 has been out for a little while—I'm not new to this camera but I'm really glad I made the jump.
Target Notes: NGC 7822, Cederblad 214, SH2-171 (the brighter emission nebula core) as well as the star cluster Berkeley 59. There are several long chains and clumps of dark nebulae, including LDN 1268, 1275, Dob 3637, 3627, 3623, many more. Nestled in that large band of dark nebulae toward the bottom is the reflection nebula GN 23.56.1. The very small circle of gray at the top left, blending in but dimmer than the nearby stars, with less contrast, is the planetary nebula Abell 1 (PLN 119+6.1). Find all of this—the nebulae and star forming complex in Cepheus near the edge of Cassiopeia.
Click for full view: