and a 640x480 ROI. With Mars being low and in the midst of its dust storm it was hard to resolve detail, but the results did show that the camera can be a bit of an all-rounder at imaging.
A few nights later we switched over to an f/2.2 Rowe-Ackermann Schmidt Astrograph (RASA) telescope. In full frame mode the camera will run outside the imaging circle on this type of setup and create vignetting, so it gave us a good chance to try the ROI modes. The first target was the Whirlpool Galaxy, M51, running 30-second exposures with the cooling set to –30° below ambient temperature. The camera performed very well, not dropping any frames when capturing in high bit mode. We moved through a few targets including M13, the Great Globular Cluster in Hercules, and M27, the Dumbbell Nebula.
In full-frame mode the camera is best suited to an aperture of around 70-100mm, so we set the camera up on a 70mm quad refractor for the next outing, going for wide-field targets like the North America Nebula. Setting longer exposure times of 180 seconds worked very well. There was no amp glow in the images in USB2 mode, even when connected via 10m USB2 extension leads, and this made processing with calibration frames very easy. Setting up with a 152mm triplet we took a chance on M31, the Andromeda Galaxy, which was rising in the north against a bit of a light blue summer night sky. Running in full-frame at 60 second exposures for 50 minutes resolved lots of nice detail in the dust lanes and the core. When we processed the images, it was nice to see some rich colours from a CMOS camera.
The ZWO may have an expensive price tag, but it really is a great performer.
M13 (left) and M27, both captured with an f/2.2 RASA; 50x30“exposures
The Moon imaged using the ZWO ASI094MC Pro and a 125 EDF refractor; 20 frames stacked from 20 captured
The North America Nebula taken through a 70mm quad refractor; a single 10-minute image
A dusty Mars; 300 frames from 3,000
M51 with an f/2.2 RASA; 100x30“shots