Introducing the ASI294MM, the monochrome version of the ASI294MC. Please note that this is the uncooled version for planetary astrophotography — the ASI294MM Pro cooled version for deep sky imaging can be found here. Some of the highlights include:
- Back-illuminated sensor – improving sensitivity and reducing noise.
- 4/3” format with 4.64 um pixel size – ideal for many types of telescopes.
- 14-bit ADC – giving high dynamic range.
- An impressive 66ke- full well capacity.
- 4144*2822 high resolution – with the Bin1 mode the camera can operate at a resolution of 8288*5644 and a pixel size of 2.3 um.
On top of this, not only does it have a very high QE value with a peak at about 90%, but also features an ultra-low readout noise of 1.2e. If you are looking for a small-format monochrome camera for planetary imaging, you can’t go wrong with the ASI294MM.
Sensor length*width: 19.1*13.0mm. Diagonal: 23mm.
HCG Mode
The full well capacity of 66387e of ASI294MM is near the top of all ASI planetary cameras. It ensures a very high dynamic range of up to 13 stops that will greatly reduce the issue of overexposed images and also help to collect richer color information.
When the gain value is set to 120, the HCG high gain mode is turned on. We’re not saying it’s magic…but we’d like to think it is pretty close. With the HCG-mode turned on, the readout noise is greatly reduced, and the dynamic range is basically unchanged.
Unlocked Bin1 Mode
Yet another perk of the ASI294MM is that the pixel size is switchable – the default setting is Bin2, but you can switch to Bin1 anytime in your astrophotography software. This changes the pixel size to 2.3um and increases resolution to 8288×5644. This is what we called “Unlocked Bin1 Mode”. The ability to unlock bin1-mode was a popular request from our customers. Of course, we listened to you and worked quickly to make it possible.
Remember that using Bin1mode will decrease the full well capacity compared to the standard bin2-mode.
Unlocked Bin1: 12bit ADC, 2.3um pixel size, 47 megapixels, 8288*5644 resolution, 14k full well capacity.
Bin2 (The default mode): 14bit ADC, 4.6um pixel size, 11.7 megapixels, 4144*2822 resolution, 66k full well capacity.
You can learn more differences between unlocked Bin1 and Bin2 modes by comparing the performance charts.
If the sampling accuracy you get with the 2.3um pixel size falls within a reasonable range, then the unlocked Bin1 mode will help you get more object details. However, you will lose dynamic range and ADC bit depth. Also, the image files you get at Bin1 will probably be around 4 times bigger than Bin2.
So in the end the unlocked Bin1 mode is double-edged, you may choose to use it or not depending on the specific circumstances during your imaging sessions.
QE Value
As ZWO’s latest BSI (backside illuminated type) mono camera, ASI294MM has very high QE performance, not only higher than its color version but even ASI1600MM. It is estimated that the QE peak value is about 90%.
ASI294MM vs ASI1600MM
USB 3.0 Port & ST4 Port
USB 3.0 Port: Providing 5Gb bandwidth to let ASI294MM run at 19fps (12bit, high speed mode) or 16.3fps (14bit, normal mode) at full resolution (11.7Mega, Bin2).
ST4 Port: Can be used to connect with auto guide port of mount for guiding.
Mechanical Diagram
