ZWO ASI294MC Pro camera
It may look much like many other ZWO cameras, but it’s hiding some surprises
0n the outside the ASI294MC Pro colour cooled camera doesn’t appear to bring much new to the company’s range, with its familiar styling, USB 2 hub and high-speed USB 3 port. But it’s on the inside that the camera starts to become much more interesting and exciting.
This is the first camera in the world to boast Sony’s new IMX294 CJK back-illuminated 3/4-inch sensor, with a diagonal size of 23.2mm and approximately 11.71MP Being part of the Pro range, the camera comes with 256MB DDR3 (double data rate type three) memory installed and a two-stage TEC cooling system that will cool it to between –35°C and –45°C below ambient temperature. You’ll need a good power supply for the camera to reach this range, though, because a power supply unit under 3A can cause software to disconnect when you’re capturing images.
HGC is a new feature with this camera and stands for high gain conversion. It switches on automatically when the camera’s gain is raised above 120. This reduces read noise to a lower level at higher gain without a loss to the dynamic range. ZWO claims this means the camera can capture 4K images, although in our experience 4K would probably be more suited to industrial applications than astronomy.
While we had a lot of warm weather over the review period, they weren’t the clearest seeing conditions, with lots of high cloud. As the Moon was also bright we set up for some imaging in the early evening and it soon became apparent that we needed to play with the camera’s settings. The initial onscreen view was very blue. On checking, the blue level was starting at 90 instead of around 55. We contacted the manufacturer and they were helpful in solving the problem. It seems it was a software glitch.
Picking out the finer details
Once sorted, the camera produced a fine image on screen and capturing was very easy using the SER file capture mode. While not the fastest camera in full resolution we only needed to capture around 200 frames and stack 50 to produce a decent image of the Moon. Switching over to planetary capture a few nights later, the camera performed well under the poor conditions and low views we had this season. Running in Region Of Interest (ROI) mode on Saturn we were able to capture some good
detail with the use of an atmospheric dispersion corrector on a 4-inch, f/11 telescope. The next target was Mars and, to be honest, we were not expecting to capture any surface detail because of the dust storm that was enveloping the planet. Using the same telescope with the addition of a 4x Powermate we set ROI capture to 640x480. In this mode the camera was recording at around 100fps. The results were especially impressive because we processed images from a few cameras that week, and the ASI294MC was the only one that picked up any surface detail on Mars.
On the next clear night, we used the camera coupled with a 2.5-inch quad refractor to image M31, the Andromeda Galaxy, and look at some live views of targets. To achieve this, we set the camera up in USB 2 mode with a 7m USB extension lead. The camera was very stable, dropping no frames in the capture software, while using a short capture time of 60 seconds meant we didn’t need to autoguide.
The camera is great for live capture and live stacking of objects, and it was a pleasure to watch a comet cross the screen in real time. This would be ideal for outreach events for showing objects to the public, or for live stacking in capture software.
The ZWO 294 MC Pro camera really has something for everyone and with CMOS sensor boundaries being pushed with each new model of camera that comes out, it makes us wonder what new developments will be coming next.
M31: 111x60”. Processed in PixInsight and Photoshop
M27: 60”x60” Processed in PixInsight and Photoshop
Mars: 5,000 frames captured, 500 frames stacked in AS2 with processing in Photoshop