A full-frame astronomy camera is often at the top of many astrophotographers’ wish lists, so when QSI released the QSI 760 – a full-frame mono camera featuring the latest CMOS sensor – we were keen to check it out.
Arriving in a large sturdy box, the first thing that struck us was the very impressive case the camera
is housed in.
Opening this, we found the sizeable camera, with filter wheel already attached, nestled securely alongside a power supply, USB cable and 2-inch nosepiece.
Screws were also supplied for attaching unmounted filters.
Setting up
Heading to the QSI website, the instruction manual was easy to find and provided clear information on how to set the QSI 760 up.
There were also detailed drawings and measurements, allowing us to precisely work out the optimal spacing for our field flattener.
To ensure that getting up and running is as simple as possible, QSI has bundled all its camera drivers into one easy install file, ensuring the correct one is always installed.
There’s also a SGPro software subscription included (a nice addition, we felt), which is downloaded separately.
The front plate of the filter wheel has a female M54 thread for either connecting the supplied 2-inch nosepiece or for directly attaching to your telescope or accessories.
Given the large-format CMOS sensor within this camera, for many users a field flattener will be a must-have accessory.
Using a separate thread adaptor (M54 to T2 in this case) and spacers, we were easily able to attach our flattener.
With the software and drivers installed, we proceeded to attach the camera to our telescope and connect the included power supply and USB 3.0 cable.
Loading up SGPro, we were pleased to see that the camera was instantly recognised by the image-sequencing software
Connecting the QSI 760 loaded a second window that gave us the option to change the gain setting. QSI has developed three pre-selectable options: high, medium and low, plus a self-customisable option.
For our test, we selected the high gain setting and connected the rest of our equipment.
How the QSI 760 performs
We first slewed over to the Elephant’s Trunk Nebula which, thanks to the QSI 760’s large 43.3mm diagonal sensor and our 478mm focal length refractor, fitted easily into our field of view.
With the camera now cooled to –10°C and holding steady, we set up a series of five-minute exposures and started our imaging session.
Monitoring the camera closely, we were pleased to see every image captured downloaded quickly and without error.
After our three-hour image run with our hydrogen-alpha filter was complete, SGPro seamlessly spun the filter wheel and selected the OIII filter, with a reassuring little click from the filter wheel as it set this next filter into place.
At the end of the night, once all images had been collected, we removed the camera and were pleased to see that the optical window was free from condensation, even after a solid eight hours of use with the cooler running on an extremely damp autumnal night.
The following morning, we transferred all of our images, including calibration frames, onto our main PC for processing.
Once stacked and with calibration frames applied, we were presented with an image rich in detail with very low noise.
This allowed us to apply a level of processing and sharpening beyond what we could normally apply, with minimal noise reduction required.
We were able to pull out fine details while keeping the image sharp and extremely clear.
Each of the imaging sessions that followed proved to be as flawless, with the data produced just as clean despite the high gain settings used.
The QSI 760 was a real joy to use and the images produced were top-class.
This camera is a professional-grade instrument, that was easy to set up and delivered outstanding results time and time again, firmly cementing itself at the top of our astronomy camera wish list.
QSI 760 sensor
The QSI 760 features the latest Sony IMX455 mono CMOS sensor, which is recognised by many as one of the best sensors on the market for astrophotography.
This full-frame sensor measures 43.3mm diagonally and offers a massive 9,576 x 6,380-pixel resolution, so will benefit from being paired to a telescope capable of illuminating the entire 44mm to take full advantage and avoid any significant vignette.
Thanks to its backside-illuminated architecture, the Sony IMX455 offers a quantum efficiency (QE) of 90%, which means it can translate 90% of the light it receives into data on the sensor.
Comparing this to other high-end CCD cameras that max out at a QE of around 77% firmly positions this camera as a market leader.
Another feature of the sensor is the exceptionally clean images it produces.
Examining a stretched five-minute dark frame captured at high gain showed low noise, zero amp glow and no artefacts or banding.
QSI 760 Best features
SGPro subscription
All purchases of the QSI 700 include a free full-featured subscription to SGPro. Once installed, you register the software using the camera’s serial number and this is then yours to keep without the need to buy an annual subscription. The subscription, however, is locked to QSI cameras only.
Cooling
The combination of a two-stage Peltier cooler, fans and large air intake means the QSI 760 can achieve temperatures down to 45°C below ambient. Throughout use and with outside temperatures still in the low double figures, the camera kept a steady –10°C during each imaging session.
Connectivity
Conveniently situated on the back of the camera is a USB 3.0 port that allows PC control, along with a secure threaded power-in socket. There are also a pair of USB 2.0 sockets, plus a threaded 2.5mm 12V power-out socket that allow control and power for ancillary devices, such as guide cameras.
Carry case
Supplied as standard is a robust and well-made hard case. Made from moulded durable plastic, it is filled with snug shaped foam to accept the camera with filter wheel attached, along with all its included accessories. This ensures there is no risk of the camera coming to harm while travelling or in storage.
Filter wheel
The QSI 700 series cameras are equipped with either a five-position or seven-position filter wheel that can accommodate 2-inch mounted filters or 50mm unmounted filters. The benefit of having the filter wheel attached is that it reduces the space between the image sensor and filter, minimising filter-induced vignette.
Key specs
- Price: £5,873 with five-position filter wheel; £6,058 with seven-position
- Sensor: Sony IMX455 full-frame mono
- Resolution: 9,576 x 6,380
- Exposure range: 1ms–24 hours
- Connectivity: USB 3.0
- Size: 190 x 200 x 140mm with integrated filter wheel
- Weight: 1.9kg
- Supplier: First Light Optics
- Email: questions@firstlightoptics.com
- www.firstlightoptics.com
This review appeared in the January 2025 issue of BBC Sky at Night Magazine
